In the name of Allah, the Gracious, the Merciful
Knowledge of God’s existence is often taken for granted by believers. The authentic religious experience—affirmed again and again in a Muslim’s daily life—makes faith in God feel so natural as to be assumed. But belief in God and the quest for existential truth is not an easy prospect for many people, especially in a social environment in which faith is derided as superstition, wishful thinking, or even as a dangerous fantasy.
In the Islamic tradition, the case for God’s existence is solid in terms of its rational foundations as well as the purpose, meaning, comfort, and guidance that it gives to our lives. The Quran inspires conviction by appealing to the aspects of the inner life of human beings, namely, to the heart and the mind. Intuition and experience work in tandem with logic and reason to arrive at a state of certainty in faith.
This understanding of conviction is reinforced by modern scientific conceptions. Cognitive scientist Justin Barrett, for example, demonstrates that belief in God—and beliefs more generally—are formed and attained in two ways: 1) non-reflective, intuitive beliefs that result from experience; and 2) reflective, conscious beliefs that result from thought.[1] The human being naturally forms beliefs from these two sources. Similarly, the case for God’s existence in the Quran and Sunnah involves both sources of beliefs: heart-based appeals based on intuition and mind-based appeals based on rational reflection.

Appealing to the Heart, Intuition, and Experience

Natural Instinct – Fiṭrat Allāh

Human beings sense the existence of God—or what they perceive as a higher power—by pure instinct, with or without a prophetic revelation to guide them. Expressions of this sensus divinitatis have appeared in cultures and religions all over the world, despite them being widely separated by time, geography, and language. In Islamic spiritual terms, this is because God took a primordial covenant with every person before the world was created that they would recognize their Creator.
Allah said:

[Prophet], when your Lord took out the offspring from the loins of the Children of Adam and made them bear witness about themselves, He said, ‘Am I not your Lord?’ and they replied, ‘Yes, we bear witness.’ So you cannot say on the Day of Resurrection, ‘We were not aware of this.’[2]

Al-Suddī (d. 745) commented on this verse, saying, “For this reason, there is no one on the face of the earth but that he knows his Lord is Allah, and no one associates idols with Him except that he will say ‘I found my forefathers following another religion.’”[3] The primordial covenant results in the innate impulse within people to seek out the higher power that they can sense, as they have done in some form or another throughout all of recorded history, to the point that some scientists today argue that belief in God or a higher power is hardwired into our genes.[4]
All true and revealed religion confirms and conforms to the human nature that the Creator instilled within us. The Quran refers to human religious nature as fiṭrat Allāh, the instinctive and inherent disposition with which God created people.
Allah said:

So [Prophet Muhammad] as a man of pure faith, stand firm and true in your devotion to the religion. This is the natural disposition God instilled in mankind—there is no altering God’s creation—and this is the right religion, though most people do not realize it.[5]

All people were born to be believers in God, and the revelations of the Prophets simply awaken and reinforce the disposition that is already inside us. Even polytheists, who believe in multiple gods and deities, often believe that there is an even higher power, an even greater God over all of them.
Allah said:

If you asked them who created the heavens and earth, they are sure to say, ‘God.’ Say, ‘Praise belongs to God,’ but most of them do not understand.[6]

And Allah said:

If you [Prophet Muhammad] ask them who created them they are sure to say, ‘God,’ so why are they deluded?[7]

Since all humans can sense a higher power, they will instinctively turn to God in times of danger. Every person, at some point in his or her life, will have an intense experience that causes a natural reaction to turn to prayer. There are many cases of people who experience a sudden brush with death that causes them to become more faithful to their religious tradition.

Allah said:

Whenever they go on board a ship they call on God, and dedicate their faith to Him alone, but once He has delivered them safely back to land, see how they ascribe partners to Him![8]

And Allah said:

Say [Prophet Muhammad], ‘Who is it that saves you from the dark depths of land and sea when you humbly and secretly call to Him [and say], ‘If He rescues us from this, we should truly be thankful’? Say, ‘God rescues you from this and every distress; yet you still worship others besides him.’[9]

And Allah said:

When something bad happens to people, they cry to their Lord and turn to Him for help, but no sooner does He let them taste His blessing then—lo and behold!—some of them ascribe partners to their Lord, showing no gratitude for what We have given them.[10]

And Allah said:

When man suffers some affliction, he prays to his Lord and turns to Him, but once he has been granted a favor from God, he forgets the One he had been praying to and sets up rivals to God, to make others stray from His path.[11]

Al-Ghazālī (d. 1111), in his autobiography, describes the innate religious disposition—that he himself experienced—as an urge for people to “seek knowledge of the reality of things.”[12] He describes this spiritual longing for truth as a “thirst” (ta’aṭṭash) that must be quenched. It is a void and emptiness in the heart, an uneasiness with existence, which must be filled by discovering meaning and purpose to life. And while reason is an important tool to achieve faith in God, it is still merely one step along the spiritual path: “Beyond the level of reason lies another level that opens another eye by which one gains insight into the Unseen and into what will occur in the future, among other things.”[13] 
Knowledge of God resides primarily in the heart and is reinforced by reason, but it is not achieved and consolidated by reason alone. There must be an authentic religious experience, the acknowledgment of greater purpose and meaning to the universe, and the taste of spiritual fruits. Hence, the early scholars of Islam defined knowledge of God not as a collection of facts and arguments, but rather as a light within the heart. Imām Mālik (d. 795) said, “Knowledge is not knowing many sayings. Verily, knowledge is only a light that Allah places in the hearts.”[14] And Ibn Rajab (d. 1393) said, “Knowledge is not memorizing many narrations or sayings, but rather it is a light that Allah places in the heart by which a servant understands the truth and he distinguishes it from falsehood.”[15] 

The Experience of Peace and Contentment

The “light” of the knowledge of God is found in the guidance, spiritual direction, and the sense of peace that believers attain by practicing Islam. It can fill the spiritual void in all of us. The greatest proof for the existence and Lordship of Allah, then, is discovered in the visceral experiences of the heart through which the believers find comfort, inner-peace, moral education, and meaning in life—the spiritual fruits of true religion.
Allah said:

A light has now come to you from God, and a Scripture making things clear, with which God guides to the ways of peace those who follow what pleases Him, bringing them from darkness out into light, by His will, and guiding them to a straight path.[16]

And Allah said:

Believers, be mindful of God and have faith in His Messenger: He will give you a double share of His mercy; He will provide a light to help you walk; He will forgive you— God is most forgiving, most merciful.[17]

And Allah said:

Truly, it is in the remembrance of God that hearts find peace.[18]

The Quran promises those who have faith that they will live a “good life” and move into an infinitely greater existence in the afterlife. The peace that believers experience in this life is only a brief taste of the peace to come in the Hereafter. Reflecting upon this fact day after day in prayer contributes to a state of calm and tranquility.
Allah said:

To whoever, male or female, does good deeds and has faith, We shall give a good life and reward them according to the best of their actions.[19]

And Allah said:

[But] you, soul at peace: return to your Lord well pleased and well pleasing; go in among My servants; and into My Garden.[20]

This is not a promise that believers will never experience adversity. Indeed, there will come times—Allah guarantees—in which the believers will be tested for their patience and perseverance. Rather, Allah promises that believers, through their spiritual practices and moral and theological education, will achieve a stable state of contentment and satisfaction with life.
Allah said:

Your Lord is sure to give you so much that you will be well satisfied.[21]

And the Prophet ﷺ said:

He has succeeded who embraces Islam, whose provision is sufficient, and who is content with what Allah has given him.[22]

Prophet Muhammad ﷺ described spiritual contentment as the “sweetness of faith,” a fruit of true religion that is to be tasted and experienced. It involves authentic encounters with the Divine by which a believer becomes grounded and certain in the truth of his or her faith.
The Prophet ﷺ said:

He has tasted the sweetness of faith who is content with Allah as his Lord, Islam as his religion, and Muhammad as his prophet.[23]

The contentment described in Islamic texts consists of a stability of being that protects believers from oscillating between extremes of momentary euphoria and sorrow, such that they can remain in a state of calm and tranquility regardless of what is happening in their lives. It is manifested in a detachment from worldly possessions and temporal concerns (zuhd), and an end to the fear of poverty. This spiritual state of being is, in fact, what the Prophet ﷺ described as true wealth.
The Prophet ﷺ said:

Wealth is not in having many possessions. Rather, true wealth is the richness of the soul.[24]

And the Prophet ﷺ said:

Wealth is in the heart and poverty is in the heart. Whoever is wealthy in his heart will not be harmed no matter what happens in the world. Whoever is impoverished in his heart will not be satisfied no matter how much he has in the world. Verily, he will only be harmed by the greed of his own soul.[25]

Consequently, those who achieve this state of being—along with their basic worldly needs—are truly the wealthiest people in the world.
The Prophet ﷺ said:

Whoever among you wakes up secure in his property, healthy in his body, and he has his food for the day, it is as if he were given the entire world.[26]

When people are consumed by wealth, possessions, and worldly status, they will inevitably experience a void that leads to unhappiness no matter how much they have. The early Muslims used to say, “If the kings of the world and their sons knew what we have of blessings and happiness, they would fight us for it with their swords.”[27] True and stable happiness is not something that we acquire “out there,” as kings and powerful leaders might imagine. The material world cannot make us happy and content for long; we have to discover the means of happiness within the heart through our relationship with the Creator. It is the free gift of Islam for all.
In this state of contentment, believers are better equipped to endure the inevitable vicissitudes of life. Hypocrites, those who are insincere in their religion, by contrast, are unable to pass through adversity with the same sense of stability and calm.
The Prophet ﷺ said:

The parable of the believer is that of a crop which withstands the wind, for the believer continues to withstand the suffering of trials. The parable of the hypocrite is that of a cedar tree, for it does not budge until it is uprooted.[28]

By tasting these spiritual fruits, the believers strengthen their conviction with every positive and meaningful experience. Knowledge of God is consolidated through these experiences much more effectively than through logical or philosophical argument.
Al-Ghazālī writes:

Hence, when you have understood the meaning of prophecy and you have abundantly examined the Quran and traditions, you will inevitably arrive at the knowledge that [Muhammad]—peace and blessings of God be upon him—embodied the highest levels of prophecy, and that is reinforced by experiencing his teachings in regards to worship and its effects on purifying the heart… Thus, when you experience that one thousand, two thousand, and many thousands of times over, you will necessarily attain knowledge in which there is no doubt.[29]

One reason this is the most effective method to strengthen faith, as demonstrated by cognitive scientists, is that the intensity of religious experiences makes them unforgettable.[30] A believer who witnesses the benefits of spiritual practice in his or her life—day after day—will attain a level of certainty and tranquility that they would never consider abandoning.

An Abandoned Instinct

Not everyone achieves an authentic religious experience or understands it in a proper theological framework. Human nature is not immune to alteration by misguided doctrines and philosophies that contradict our healthy instincts, even ideas that claim a basis in theism.
The Prophet ﷺ said:

No one is born except upon natural instinct. Then his parents turn him into a Jew or a Christian or a Magian. As an animal produces their young with perfect limbs, do you see anything defective?[31]

In this tradition, the Prophet ﷺ tells us that everyone is born to accept the simple, natural worship of one unique, powerful, and benevolent Creator. However, for various reasons, people invent religious doctrines that anthropomorphize God (ascribe human features to Him), or ascribe divine attributes to created beings (such as deifying saints and sages), or deny the Creator altogether.
When human nature and intuitive belief in one God are corrupted, either by negative experiences or the influence of others, then logical arguments may be required for a person to return back to his or her natural state.
Ibn Taymiyyah (d. 1328) writes:

The establishment and recognition of the Creator is a fundamental instinct in human nature, even though some people have done something to corrupt their nature such that they need an argument to achieve knowledge of God. This is the opinion of the majority of people, as well as the skilled debaters, that knowledge of God is sometimes achieved effortlessly and other times by argument, as was recognized by more than one of the theologians.[32]

Our intuitive beliefs, which we gain from our natural disposition and experiences, serve to anchor and inform the beliefs that we gain through reflection and conscious, rational deliberation.[33] In this way, reading and reflecting on the Quran builds upon intuitive experiences of the heart by appealing to the mind and the power of reason.

Appealing to the Mind, Reason, and Logic

Cosmological Discourse

The question that most human beings eventually ask themselves is about the nature of existence: Why am I here? Why is there a world and a universe? Why is there something and not nothing?
The Quran addresses this question with a cosmological discourse, a reminder that it was God who created everything and caused it to be. Human beings are asked to reflect upon the nature of their existence and the universe. Is it really plausible, sensible, and intuitive that the universe appeared arbitrarily for no reason?
Allah said:

Have they not thought about their own selves? God did not create the heavens and earth and everything between them without a serious purpose and an appointed time, yet many people deny that they will meet their Lord.[34]

Our intuition and experience tell us that effects have causes; things come to be because something made them that way. Since the universe is one giant series of causes and effects, it is reasonable to conclude that it had an original cause that set it all in motion.
Allah said:

Were they created out of nothing? Were they the creators? Did they create the heavens and the earth? No! They do not have faith.[35]

These verses posit three possibilities: 1) the universe appeared without any agent to bring it into existence; 2) people created themselves; or by implication 3) the universe must have been created.
The first two propositions are impossible. It could not be the case that the universe appeared from nothing without any reason, purpose, or force to inject it with its energy and direction. Everyday experience informs us that all things we witness in life, every effect we see, must have an explanation at some level. The second proposition, that people created themselves, can be dismissed on its face. As such, the only reasonable conclusion is that the universe was caused—it was created—it was made to exist by something greater and more powerful than itself.
Ibn Ḥajar (d. 1449) explains the meaning of these verses by quoting the scholar Al-Khaṭṭābī:

It is said the meaning [of the verse] is: Were they created without a creator? That is impossible, as they must have a creator. If they deny the Creator, then they must have created themselves, and that proposition is even more foolish and false, for how can something without existence create anything? If they reject these two opinions [that they came to be without a creator or they created themselves], then the proof is established upon them that they were in fact created.[36]

Scholars derive from these verses and others a logical train of thought, sometimes referred to as the cosmological argument, which determines that God, as the uncaused cause or first cause, is the most reasonable answer to the existential question. İsmail Latif Hacınebioğlu summarizes the logic of the argument in the following steps:

Everything in the universe that has a beginning must have a cause.

The universe began to exist.

Therefore the beginning of the existence of the universe must have been caused by something.

The only such cause must be an uncaused cause, or God.[37]

This line of thinking is acceptable to the mind and it finds validation in human intuition and experience. It sufficiently answers the question of why anything exists in the first place. Jubair ibn Muṭ’im (d. 677) reported that he heard the Prophet ﷺ reciting these verses in the evening prayer, and he said, “My heart was about to fly!”[38] The argument in this passage was so compelling that Jubair embraced Islam.[39]
A version of this argument was used by the great jurist and theologian Abū Ḥanīfah (d. 767) in his debate with philosophers who were skeptical about the existence of God:

It was reported from Abū Ḥanīfah that some philosophers (ahl al-kalām) intended to discuss with him the establishment of the existence of one Creator. Abū Ḥanīfah said, ‘Tell me before we speak on this matter about a ship on the Tigris river moving by itself and filled with food, goods, and other materials, then it goes back by itself, then anchors itself, then unloads itself and continues to do all of this without anyone to manage it.’ They said, ‘This could never happen.’ Abū Ḥanīfah said, ‘If it is impossible for a ship, then how is it possible for the entire world in all of its vastness?’[40]

Ibn Al-Qayyim (d. 1350) uses a similar example of a watermill spinning on its own, producing, harvesting, and distributing its crops without anyone to guide it:

What do you say about a watermill revolving over a river in perfection? Its tools are perfected, its parts measured with excellence, and it is so obvious such that no observer can find fault in its parts or its form. It presides over a grand garden within which are every kind of fruit and crops, watering them as needed. Within this garden, its shrubbery is gathered and its maintenance is assured for its well-being. Its produce is excellent and guaranteed, and all of its needs are well served. Thus, nothing of it is left disordered and none of its fruit is left to rot. Then, the value of everything produced is divided according to their needs and necessities, divided by every type and distributed, and this distribution occurs in this manner at all times. Do you find this arrangement to have a creator or harvester or manager? Or, is the arraignment of that watermill and garden without an actor or maintainer or manager? What do you find that your mind tells you in that case and how could you explain it?[41]

Common sense tells us that the ship or the watermill must have been made to move by something outside of itself. Established scientific principles agree. The great physicist Sir Isaac Newton’s first law of motion states: “Every object persists in its state of rest or uniform motion in a straight line unless it is compelled to change that state by forces impressed on it.”[42] In other words, things in the universe do not move or change their movements unless an external force acts upon them. This is true of everything in the universe, and it is just as true for the universe itself as a whole.
Those who deny the existence of the Creator attempt to challenge the a priori premise that the universe has a definite beginning. Their argument is that the universe has always existed in an endless series of causes, or an infinite regression, without the need for a first cause to set it in motion. Besides being counter-intuitive—as all things we experience in life had a beginning at some point—modern physics and cosmology now largely accept the premise of the cosmological argument as fact. The “big bang” theory postulates that the universe began from a singularity somewhere between 12 and 14 billion years ago.[43]
Even if we accept the idea of an infinite regression for the sake of argument, and despite the lack of scientific or intuitive evidence for it, that does not discount the need for a cause beyond time and space to produce and sustain it. Polymath and philosopher G.W. Leibniz (d. 1716) asserts that an infinite series must still necessarily have a sufficient reason for its existence:

Let us suppose that a book on the elements of geometry has always existed, one copy always made from another. It is obvious that although we can explain a present copy of the book from the previous book from which it was copied, this will never lead us to a complete explanation, no matter how many books back we go, since we can always wonder why there have always been such books, why these books were written, and why they were written the way they were. What is true of these books is also true of the different states of the world, for the state which follows is, in a sense, copied from the preceding state, though in accordance with certain laws of change. And so, however far back we might go into previous states, we will never find in those states a complete explanation [ratio] for why, indeed, there is any world at all, and why it is the way it is… From this it follows that even if we assume the eternity of the world, we cannot escape the ultimate and extramundane reason for things, God.[44]

In the same vein, physicist Don Page gives the example of an artist drawing a circle on a canvas; the circle has no beginning or end, yet it still required an external artist to draw it.[45] The existence of the universe itself, regardless of its finite or infinite nature, must have had a Creator to set the chain of causes in motion.
Nevertheless, the cosmological argument by itself is only one piece in a much larger discourse on the nature of existence. The Quran complements the discussion with an even greater and more compelling teleological discourse—that the world was designed.

Teleological Discourse

The very fabric of the cosmos, from the macroscopic stars to the microscopic world of microbes and everything in between, contains a set of universal, natural laws that produce order. The result of these laws is that many things in the universe exhibit identifiable purpose. Our eyes were made to see. Our ears were made to hear. Our lungs were made to breathe. Our trees were made to produce fruit and clean air. Our water was made to sustain life, and so on. With so many clear instances of purpose that we repeatedly experience in the different parts of the universe, it is only logical to conclude that the entire universe itself exists as it is for a purpose.
Indeed, teleological language is unavoidable in daily life and especially in life sciences. Biologists and medical professionals speak of the “role” and “function” of various organs (who assigned its role and function?), as well as genetic “codes” and “information” (who coded it and informed it?). Charles Darwin himself, often held up as a champion of atheist philosophies, was unable to convey his scientific ideas without frequent recourse to the language of design and purpose.[46] It is natural and intuitive for us to recognize the teleology of the universe.
Accordingly, the Quran persistently draws attention to signs (āyāt) in nature that demonstrate the grand design and power of the Creator. We are called to engage in thoughtful reflection (tafakkur) upon all of these signs as a means of recognizing our purpose and attaining conviction.
Allah said:

There truly are signs in the creation of the heavens and earth, and in the alternation of the night and day, for those with understanding, who remember God standing, sitting, and lying down, who reflect on the creation of the heavens and earth: ‘Our Lord! You have not created all this without purpose—You are far above that!—so protect us from the torment of the Fire.’[47]

True faith, then, is not the result of an abandonment of reason, as some people imagine. The apparent dichotomy between religion and science is a false one.[48] Rather, using the faculty of reason, in concert with a sound heart, is a path to God and an Islamic virtue. Abu Al-‘Alā, one of the early Muslims, used to say, “A worshipper is given nothing better after Islam than to be provided with a sound mind.”[49] 
Towards this end, the Quran explicitly appeals to the reason (al-’aql) of its readers and particularly their ability to reflect upon the teleology of existence.
Allah said:

In the creation of the heavens and earth; in the alternation of night and day; in the ships that sail the seas with goods for people; in the water which God sends down from the sky to give life to the earth when it has been barren, scattering all kinds of creatures over it; in the changing of the winds and clouds that run their appointed courses between the sky and earth: there are signs in all these for those who use their minds.[50]

And Allah said:

One of His signs is that He created you from dust and—lo and behold!—you became human and scattered far and wide. Another of His signs is that He created spouses from among yourselves for you to live with in tranquility: He ordained love and kindness between you. There truly are signs in this for those who reflect. Another of His signs is the creation of the heavens and earth, and the diversity of your languages and colors. There truly are signs in this for those who know. Among His signs are your sleep, by night and by day, and your seeking His bounty. There truly are signs in this for those who can hear. Among His signs, too, are that He shows you the lightning that terrifies and inspires hope; that He sends water down from the sky to restore the earth to life after death. There truly are signs in this for those who use their reason.[51]

And Allah said:

There are, in the land, neighboring plots, gardens of vineyards, cornfields, palm trees in clusters or otherwise, all watered with the same water, yet We make some of them taste better than others: there truly are signs in this for people who reason.[52]

And Allah said:

By His command He has made the night and day, the sun, moon, and stars all of benefit to you. There truly are signs in this for those who use their reason.[53]

There are signs of God in everything that we see at every level: the sun, the moon, the stars, the planets, the night and day, the mountains, the oceans, the wind, the clouds, the rain, every plant and animal, all types of fruit and food and drink, the miracles of the human genome, virtues such as love, wisdom, and beauty, and much more than can be counted. The more we examine these signs and think deeply about them, the more it will reinforce our conviction.
Allah said:

We shall show them Our signs on the far horizons and in themselves, until it becomes clear to them that this is the Truth. Is it not enough that your Lord witnesses everything?[54]

Highlighting the signs of God’s work in nature is the primary and most powerful rational method of confirming the existence of the Creator. Ibn Taymiyyah writes, “Affirming the Creator by means of signs is an obligation, as it has been revealed in the Quran and Allah has made it instinctual to his servants. Though deductive arguments may be correct, their usefulness is lacking.”[55] More complicated philosophical arguments, while not necessarily incorrect, are not as potent since most common people are not trained in the terminologies and methods of philosophical argumentation. In the same passage, Ibn Taymiyyah goes on to criticize the arguments of Ibn Sīnā (d 1037), Al-Rāzī (d. 1210), and others who put forth purely philosophical arguments for the existence of God, which were weak or ineffective in his estimation.
Along these lines, the great Imāms were often asked why they believed in the Creator in the first place, and they would respond by calling attention to the signs of God.
Imām Mālik (d. 795) was asked by Caliph Hārūn Rashīd about the existence of the Creator, and Mālik told him to seek evidence in the different languages, different voices, and different melodies of creatures.[56]
Imām Al-Shāfi’ī (d. 820) was asked about the existence of the Creator and he replied, “The leaves of a berry bush all have one taste. Worms eat it and produce silk. Bees eat it and produce honey. Goats, camels, and cows eat it and deliver offspring. Deer eat it and produce musk. Yet, all of these come from one thing.”[57] The simple miracle of the leaves of a bush, and every other miracle it produces, indicates that it was designed for this very purpose.
Imām Aḥmad (d. 855) was asked about the existence of the Creator and he replied, “Consider a smooth, impenetrable fortress without any doors or exits. The outside is like white silver and the inside is like pure gold. It is built in this way and, behold! Its walls crack and out comes an animal hearing and seeing with a beautiful shape and a pleasant voice.”[58] Aḥmad was referring to the natural wonder of a baby chick emerging from her mother’s egg.
The powerful evidence contained in God’s signs requires no specialized philosophical training or knowledge to understand them and believe in them. As we have said, it is natural and intuitive to recognize them. In a well-known story, a Bedouin—a member of the nomad tribes who were usually illiterate—was once asked about the existence of the Creator and he replied, “Glory be to Allah! The camel’s droppings testify to the existence of the camel, and the footprints testify to existence of the walker. A sky that holds the stars, a land that has fairways, and a sea that has waves? Does not all of this testify to the existence of the Kind, the Knowing?”[59] 
The simplicity of the teleological argument was even put into pithy poetic verse by Ibn Mu’taz (d. 908):
Strange how the God is disobeyed,
And strange the dispute of the disputer (jāḥid),
In everything there is a sign,
To show that He is One (Wāḥid).[60]
After mentioning all of these anecdotes in his exegesis, Ibn Kathīr (d. 1373) further comments:

The running rivers that travel from area to area with benefit, and what Allah has produced from the earth of various animals and plants of different tastes, scents, shapes, and colors, and the unity of the soil and water; all this demonstrates the existence of the Creator and His awesome power, His wisdom and mercy with His creation, His kindness, good treatment, and benevolence with them. There is no God besides Him. There is no Lord like Him. I depend upon Him and I turn to Him. The verses in the Quran indicating this are very plentiful.[61]

At this point, someone might accept the idea that the universe was indeed designed, but why should it be only one Creator? Why not many different gods? The answer to this question lies in the fact that the natural laws of the universe are deliberate, consistent, and united in their purpose.
Allah said:

If there had been in the heavens or earth any gods but Him, both heavens and earth would be in ruins: God, Lord of the Throne, is far above the things they say.[62]

All of the forces in the universe work together towards a common end: the creation of the world and the sustaining of life. We can infer that there is a single intelligent force behind all of it. There is nothing to suggest that one god created gravity, another created electromagnetism, and other gods govern every other natural force, all for a common unified purpose. We would expect the existence of many creators to result in arbitrary, or perhaps competing, natural phenomena. That explanation may have seemed plausible to ancient societies for which nature appeared to have no discernible order.

Scientific Validation

As science has advanced considerably, we now take for granted our recognition of the consistency and universality of natural laws. In fact, science could not advance at all without assuming uniform patterns within the fabric of the universe. The law of gravity applies in the same manner to any object with mass, regardless of its location on earth or in deep space. Ironically, modern science implicitly depends upon a monotheistic premise.
Physicists like Paul Davies note that the natural laws of the universe require a plausible explanation. It is simply irrational—and unscientific—to assume the laws of the universe appeared as they are for no reason:

The most refined expression of the rational intelligibility of the cosmos is found in the laws of physics, the fundamental rules on which nature runs. The laws of gravitation and electromagnetism, the laws that regulate the world within the atom, the laws of motion—all are expressed as tidy mathematical relationships. But where do these laws come from? And why do they have the form that they do? . . . Over the years I have often asked my physicist colleagues why the laws of physics are what they are. The answers vary from ‘that’s not a scientific question’ to ‘nobody knows.’ The favorite reply is, ‘There is no reason they are what they are—they just are.’ The idea that the laws exist without reason is deeply anti-rational. After all, the very essence of a scientific explanation of some phenomenon is that the world is ordered logically and that there are reasons things are as they are. If one traces these reasons all the way down to the bedrock of reality—the laws of physics—only to find that reason then deserts us, it makes a mockery of science.[63]

Tracing the series of explanations for why things are as they are leads to the reasonable conclusion that the universe is designed for life. Scientists have referred to this as the finely-tuned universe or the anthropic principle, that the laws of nature are configured in such astonishingly precise measurements in order for the universe to exist and for life to thrive. According to physicist and philosopher Robin Collins, “If the initial explosion of the big bang had differed in strength as little as one part in 10⁶⁰, the universe would have either quickly collapsed back on itself, or expanded too rapidly for stars to form. In either case, life would be impossible.” The chance of this happening is like firing a bullet at a one-inch target twenty billion light-years away and hitting the mark.[64]
Collins elaborates on this thinking by examining six compelling cases of fine-tuning built into the fabric of the universe:
  1. The cosmological constant.
  2. The strong nuclear and electromagnetic forces.
  3. Carbon production in stars.
  4. The proton-neutron mass difference.
  5. The weak nuclear force.
  6. Gravity.[65]
Each of these forces and phenomena are balanced in a way that produces the wondrous universe in which we live. It is hardly rational or logical to assume—without hard evidence—that all of these natural laws, with every miracle that they produce, appeared without cause or purpose.
In the scientific community, the idea of a finely-tuned universe has its critics and skeptics. Even so, the abundant evidence in nature and the plausible, rational argument for theism it produces cannot honestly be denied. Antony Flew was a long-time atheist philosopher who wrote against theism for over fifty years, but upon examining the emerging evidence of fine-tuning he later came to conclude that some intelligence beyond humanity must account for the origins of life and the complexity of the universe.[66] Theism, he writes, cannot be dismissed as wishful thinking or superstition:

Whatever the merits or demerits of this fine tuning argument in the context of attempts to construct a natural (as opposed to a revealed) theology, it must at once be allowed that it is reasonable for those who believe—whether rightly or wrongly—that they already have good evidencing reasons for accepting the religious teachings of any one of the three great revealed theistic religions—Judaism, Christianity, and Islam—to see the fine-tuning argument as providing substantial confirmation of their own antecedent religious beliefs.[67]

Perhaps the real superstition, then, is the ungrounded dogma that the universe is a purposeless accident.
Allah said:

They say, ‘There is only our life in this world: we die, we live, nothing but time destroys us.’ They have no knowledge of this: they only follow guesswork.[68]

Al-Ṭabarī comments on this verse, saying, “[The verse] means they do not have knowledge with certainty, as they only assume so without a message coming to them from Allah, nor any demonstrable proof with them to verify it.”[69]
In other words, the anti-theists themselves have a worldview without a strong foundation in evidence and logic. Much of their momentum as a movement involves misrepresenting theistic positions (a “straw-man” fallacy), or redirecting attention towards the irrational and hypocritical behavior of some self-identified believers (a “red-herring” fallacy). In reality, it is impossible to conclusively determine or prove that God does not exist. Even Richard Dawkins, one of the most strident atheists and harshest critics of religion, admitted that he could not be sure that God—and by extension the Hereafter—does not exist.[70]
Yet the denial of theism—or at least the existence of a higher power and purpose—has always been, and will continue to be, entertained only by a minority of humanity overall, as belief in God is hardwired into our human nature and can never be erased entirely. Even if religious faith recedes for a time, it can and will always be revived again.

God in the Unseen

Lastly, a common objection to the belief in God is that God cannot be directly seen or perceived. Why should we believe in what we cannot see? The answer is that God, as the Almighty Supreme Being, unique and otherworldly, exists beyond the cosmic veil in the Unseen (al-ghayb). Although we cannot see God directly, we can reasonably infer His existence by the signs of His design in the world.
The proposition that God cannot be seen, and therefore should not be believed in, is nothing new or original put forth by the “death of God” philosophers. It was said in the time of Prophet Muhammad ﷺ as well.
Allah said:

Those who do not fear to meet Us say, ‘Why are the angels not sent down to us?’ or ‘Why can we not see our Lord?’ They are too proud of themselves and too insolent.[71]

The argument of the Meccan idolaters was not proposed as an honest question, but rather as an excuse not to practice faith. No one can logically claim that the inability to see something confirms its non-existence. There are many things in the world we cannot see, but in which we believe, because we deduce their existence from their signs or effects. We cannot see the wind, but we see it blowing the grass and trees. We cannot see radio waves, but we can see the results of their transmission.
By definition, science cannot “prove” or “disprove” the existence of God in a direct and conventional way, such as in a laboratory. Science only deals with the physical, tangible world of things that can be measured. God is beyond the physical world and beyond measurement. Those who pointed their telescopes to the heavens and disbelieved in the divine when they saw no bearded man sitting upon a cloud “have no grasp of God’s true measure.”[72]
Consider for a moment the world of microbes that live in a petri dish being studied by scientists. The organisms are so small that the scientists must use powerful instruments to observe them. Is it possible for the organisms to perceive that the scientists are there? Is it possible for the organisms to measure the scientists in any meaningful way? The sheer difference in scale precludes the ability of microbes to fully comprehend a reality that is beyond their reach.
Our relation to God is similar to those organisms observed by the scientists, except that our finite existence is even feebler as compared to the infiniteness of the Supreme Being. We can become aware of God through His signs, but we can never comprehend the full measure of God. The reality of God is too vast to be seen directly or measured with instruments. If the cosmic veil had been lifted, the awesomeness that is God Almighty would eradicate us.
The Prophet ﷺ said:

His veil is light. If He were to remove the veil, the splendor of His countenance would consume His creation as far as can be seen.[73]

Hence, God does not speak directly to human beings, but rather through revelations delivered to Prophets.
Allah said:

It is not granted to any mortal that God should speak to him except through revelation or from behind a veil, or by sending a messenger to reveal by His command what He will: He is Exalted and Wise.[74]

The words revealed to the Prophets—whether it was Abraham, Moses, Jesus, or Muhammad, peace and blessings be upon them all—have moved the world and continue to shape history, to provide comfort and guidance to millions of people all over the world. The guiding hand of the Almighty, though operating from the Unseen, is there for all to see.

Conclusion

The case for God’s existence in the Quran and Sunnah is straightforward, easy to comprehend, and supported by logic and sound reasoning. Conviction in faith is attained when the basic faculties of the heart and mind combine in reflection upon the facts of existence and the message of the Prophets. It does not require any special training or philosophy to arrive at the truth of theism; the evidence and arguments are accessible to all people regardless of their level of education. Such is a manifestation of the wisdom and mercy of the Creator, who created the world so that He would be known, as a stepping-stone towards the greater life to come in the Hereafter. The spiritual path does require, however, a sustained and patient effort to seek out the truth, to answer the most important existential questions, and to remove specious doubts.
Yet the case will not be accepted by everyone. They will either reject the logic or posit their own explanations of the universe that do not include God. And there are even more obstacles that turn people away from faith, and from Islam specifically: the hypocrisy of some believers, trauma endured at their hands, or any number of other doubts.[75] Knowledge of the Divine is a light that God places in the hearts of people, first and foremost, and no amount of argumentation can insert His light into the hearts of those who, for whatever reason, cannot see it. Our role as believers is to be the best examples of our faith that we can possibly be, to make the case for Islam with grace, compassion, and beautiful preaching, to offer good will to all and to pray for the guidance of those who need it.
Success comes from Allah, and Allah knows best.

Notes

[1] Barrett, Justin L. Cognitive Science, Religion, and Theology: From Human Minds to Divine Minds. (West Conshohocken, PA: Templeton Press, 2011), 11.

[2] Sūrat al-‘Arāf 7:172; Abdel Haleem, M. A. The Qur’an: English translation and parallel Arabic text. (Oxford: Oxford University Press, 2010), 174.

[3] al-Ṭabarī. Jāmiʻ al-Bayān ‘an Ta’wīl al-Qur’ān. Bayrūt: Mu’assasat al-Risālah, 2000), 10:561, verse 7:172.

[4] Hamer, Dean H. The God Gene: How Faith Is Hardwired into Our Genes. (New York: Doubleday, 2004), 6.

[5] Sūrat al-Rūm 30:30; Abdel Haleem, The Qur’an, 408.

[6] Sūrat Luqmān 31:25; Abdel Haleem, The Qur’an, 414.

[7] Sūrat al-Zukhruf 43:87; Abdel Haleem, The Qur’an, 496.

[8] Sūrat al-‘Ankabūt 29:65; Abdel Haleem, The Qur’an, 404.

[9] Sūrat al-An’ām 6:63-64; Abdel Haleem, The Qur’an, 136.

[10] Sūrat al-Rūm 30:33-34; Abdel Haleem, The Qur’an, 409.

[11] Sūrat al-Zumar 39:8; Abdel Haleem, The Qur’an, 460.

[12] al-Ghazzālī, ʻAbd al-Ḥalīm. al-Munqidh min al-Ḍalāl. al-Qāhirah: Dār al-Kutub al-Ḥadīthah, [1972]), 111.

[13] al-Ghazzālī, al-Munqidh min al-Ḍalāl, 182.

[14] ʻIyāḍ, [al-Qāḍī] Abū al-Faḍl. al-Ilmāʻ ilā Maʻrifat Uṣūl. al-Qāhirah: Dār at-Turāt̲h, [1970]), 217.

[15]  Ibn Rajab, and Muḥammad N. Ajmaī. Bayān Faḍl ʻilm al-Salaf ʻalá ʻilm al-Khalaf. (Bayrūt, Lubnān: Dār al-Bashāʼir al-Islāmīyah, 1995), 58.

[16] Sūrat al-Mā’idah 5:15-16; Abdel Haleem, The Qur’an, 111.

[17] Sūrat al-Ḥadīd 57:28; Abdel Haleem, The Qur’an, 542.

[18] Sūrat al-Ra’d 13:28; Abdel Haleem, The Qur’an, 253.

[19] Sūrat al-Naḥl 16:97; Abdel Haleem, The Qur’an, 279.

[20] Sūrat al-Fajr 89:27-30; Abdel Haleem, The Qur’an, 595.

[21] Sūrat al-Ḍuḥa 93:5; Abdel Haleem, The Qur’an, 597.

[22] Muslim, Ibn H. Ṣaḥīḥ Muslim. ([Bayrūt]: Dār Iḥyā’ al-Kutub al-‘Arabīyah, [1955]), 2:730 #1054.

[23] Muslim, Ṣaḥīḥ Muslim, 1:62 #34.

[24]  al-Bukhārī, Muḥammad I. Ṣaḥīḥ al-Bukhārī. (Bayrūt: Dār Ṭawq al-Najjāh, [2002]), 8:95. #6446.

[25] al-Ṭabarānī, Sulaymān ibn Aḥmad, and Ḥamdī ʻAbd al-Majīd Salafī. al-Mu’jam al-Kabīr. (al-Qāhirah: Maktabat Ibn Taymīyah, 1994), 2:154 #1643; declared authentic (ṣaḥiḥ) by Al-Albānī in Ṣaḥīh al-Jāmi’ al-Ṣaghīr wa Ziyādatihi ([Dimashq]: al-Maktab al-Islāmī, 1969), 2:1289 #7816.

[26] al-Tirmidhī, Ibn ʻĪsá. Sunan al-Tirmidhī. (Bayrūt: Dār al-Ġarb al-Islāmī, 1998), 4:152 #2346; declared fair (ḥasan) by Al-Tirmidhī in his comments.

[27] Ibn ‘Asākir. Tārīkh Dimashq. (Bayrūt: Dār al-Fikr, 1995), 6:303.

[28] al-Bukhārī, Ṣaḥīḥ al-Bukhārī, 7:114 #5643.

[29] al-Ghazzālī, Al-Munqidh min al-Ḍalāl, 185-186.

[30] Barrett, Justin L. Why Would Anyone Believe in God? (Walnut Creek, CA: AltaMira Press, 2004), 66.

[31] al-Bukhārī, Ṣaḥīḥ al-Bukhārī, 2:94 #1358.

[32] Ibn Taymīyah, Taqī al-Dīn. Majmū’ al-Fatāwà. (al-Madīnah al-Munawwarah: Majmaʻ al-Malik Fahd li-Ṭibāʻat al-Muṣḥaf al-Sharīf, 1995), 16:328.

[33] Barrett, Cognitive Science, Religion, and Theology, 49.

[34] Sūrat al-Rūm 30:8; Abdel Haleem, The Qur’an, 406

[35] Sūrat al-Ṭūr 52:35-36; Abdel Haleem, The Qur’an, 526.

[36] Ibn Ḥajar. Fatḥ al-Bārī bi-Sharḥ al-Bukhārī. (Bayrūt, Lubnān: Dār al-Ma’rifah, 1959), 8:603.

[37] Hacınebioğlu, İsamail L. Does God Exist? : Logical Foundations of the Cosmological Argument. (Istanbul: Insan, 2008), 188.

[38] al-Bukhārī, Ṣaḥīḥ al-Bukhārī, 6:140 #4854.

[39] Ibn Kathīr, Ismāʻīl ibn ʻUmar. Tafsīr al-Qurān al-‘Aẓīm. (Bayrūt: Dār al-Kutub al-ʻIlmīyah, 1998), 7:406, verse 52:35.

[40] Ibn Abī al-‘Izz, and Aḥmad al-Ṭaḥāwī. Sharḥ al-‘Aqīdah al-Ṭaḥāwīyah. (Bayrūt: Muʼassasat al-Risālah, 1997), 1:36.

[41] Ibn al-Qayyim. Miftāḥ Dār al-Sa’ādah wa Manshūr Wilāyat al-‘Ilm wa al-Idārah. (Bayrūt, Lubnān : Dār al-Kutub al-ʻIlmīyah, 2002), 1:214.

[42] “Newton’s Laws of Motion.” National Aeronautics and Space Administration (NASA). Accessed 23 December 2016. www.grc.nasa.gov/www/k-12/airplane/newton.html.

[43] “Big Bang Cosmology.” National Aeronautics and Space Administration (NASA). Accessed 23 December 2016. map.gsfc.nasa.gov/universe/bb_theory.html.

[44] Leibniz, Gottfried W, Roger Ariew, and Daniel Garber. Philosophical Essays. (Indianapolis: Hackett Publishing Company, 1989), 149-150.

[45] Overman, Dean L. A Case for the Existence of God. (Lanham, Md: Rowman & Littlefield, 2009), 40.

[46] Hanby, Michael. No God, No Science?: Theology, Cosmology, Biology. (Malden, MA: Wiley-Blackwell, 2013), 212.

[47] Sūrat ‘Āli ‘Imrān 3:190-191; Abdel Haleem, The Qur’an, 76.

[48] Sacks, Jonathan. The Great Partnership: Science, Religion, and the Search for Meaning. (New York: Schocken Books, 2011), 1.

[49] Ibn Abī Shaybah. Al-Muṣannaf. (Riyādh: Maktabat al-Rushd Nāshirūn, 2006), 5:266 #25942.

[50] Sūrat al-Baqarah 2:164; Abdel Haleem, The Qur’an, 26.

[51] Sūrat al-Rūm 30:20-24; Abdel Haleem, The Qur’an, 407.

[52] Sūrat al-R’ad 13:4; Abdel Haleem, The Qur’an, 250.

[53] Sūrat al-Naḥl 16:12; Abdel Haleem, The Qur’an, 269.

[54] Sūrat Fuṣṣilat 41:53; Abdel Haleem, The Qur’an, 483.

[55] Ibn Taymiyyah, Majmū’ al-Fatāwà, 1:48.

[56] Ibn Kathīr. Tafsīr al-Qurān al-‘Aẓīm, 106.

[57] Ibid., 106-107.

[58] Ibid., 107.

[59] Ibid., 106.

[60] Ibid., 107.

[61] Ibid., 1:107.

[62] Sūrat al-Anbiyā’ 21:22; Abdel Haleem, The Qur’an, 324.

[63] Overman, A case for the existence of God, 42.

[64] Murray, Michael J (ed.). Reason for the Hope Within. (Grand Rapids, Michigan: W.B. Eerdmans, 1999), 49.

[65] Manson, Neil A. God and Design: The Teleological Argument and Modern Science. (London: Routledge, 2003), 179-190.

[66] Wood, W J. God. (Durham: Acumen, 2011), 29.

[67] Flew, Antony. God & Philosophy. (New York: Prometheus Books, 2005), 11.

[68] Sūrat al-Jāthiyah 45:24; Abdel Haleem, The Qur’an, 502.

[69] al-Ṭabarī, Jāmiʻ al-Bayān, 22:80.

[70] Bingham, John. “Richard Dawkins: I can’t be sure God does not exist.” The Telegraph. Accessed 23 December 2016. http://www.telegraph.co.uk/news/religion/9102740/Richard-Dawkins-I-cant-be-sure-God-does-not-exist.html.

[71] Sūrat al-Furqān 25:21; Abdel Haleem, The Qur’an, 363.

[72] Sūrat al-Anām 6:91; Abdel Haleem, The Qur’an, 140.

[73] Muslim, Ṣaḥīḥ Muslim, 1:161 #179.

[74] Sūrat al-Shūrā 42:51; Abdel Haleem, The Qur’an, 489.

[75] Youssef Chouhoud, “Modern Pathways to Doubt in Islam.” Yaqeen Institute for Islamic Research. Accessed 23 December 2016. www.yaqeeninstitute.org/publications/modern-pathways-to-doubt-in-islam/