Prove to Me That God Exists: Getting Clear on Atheism, Agnosticism, and a Few Other Matters

By Paul Copan


After speaking to the Philomathean Society—a debate club—at Union College in Schenectady, New York, a student approached me and demanded: “Prove to me that God exists.”

I asked him, “What would you take as an acceptable level of proof?”

The student paused and eventually responded, “I guess I haven’t even thought about that.” The conversation, which turned out to be cordial enough, died out shortly thereafter.

Usually, when skeptics ask us Christians for “proof,” they are usually calling for “scientific proof” for God’s existence, objective moral values, the soul, or life after death. We have come to expect such challenges in an age of scientism—the belief that science, and thus “scientific proof”—can alone yield knowledge. Since the 9/11 attacks, this “enlightened” modern criterion for knowing has been reinforced by the “New Atheists”—Daniel Dennett, Richard Dawkins, Sam Harris, and (the late) Christopher Hitchens. Richard Dawkins, for example, writes “Scientific beliefs are supported by evidence, and they get results. Myths and faiths are not and do not.”1

Such critics assume that Christians and other theists have a special burden of proof to bear to show that God exists. All the while, atheists may be sitting back and assessing whatever the theist can come up with. And if nothing is forthcoming or if it is not sufficiently strong evidence to their mind, then they typically think themselves properly justified in their rejection of God. But is that the proper protocol demanded by rationality and other appropriate considerations?

In response to such challenges, it is wise to sort out and define our terms. What do we mean by science? What is knowledge? What is the difference between an atheist and an agnostic? We should also get clear on “the rules of engagement” so that we can fair-mindedly converse about such topics.

Science, Scientism, and Knowledge

First, let us clear away some confusions about science and knowledge. To do so, we should distinguish between science and scientism. As Christian philosopher of science Del Ratzsch defines science, it is the attempted objective study of the natural world and natural phenomena whose theories and explanations do not normally depart from the natural world.2

Now, some will quibble with the word “normally.” This, they suggest, “smuggles God into science.” But to think this is a mistake. To insist that all that happens in the physical world demands a physical explanation is question-begging—that is, assuming what one wants to prove. But if God exists and has created and designed the universe, it would be quite fitting for him to act directly in the world according to his good and wise purposes. What’s more, God’s acts in the world would in principle leave detectable traces of such activity on or in the physical world—whether the Big Bang, the universe’s fine-tuning , or miracles like turning water into wine. For example, Craig Keener ’s two-volume book Miracles is a work that provides massive documentation for these physical traces—for example, healings and resuscitations from death carried out in Jesus’s name. Keener mentions possessing the actual x-rays from before and immediately after a number of these prayers for healing. 3 So while most things that happen in the physical world have physical explanations, to demand only physical explanations for any physical phenomena actually goes beyond science to the rigid demands of scientism that presupposes that the physical world is all there is (i.e., naturalism). In the interests of pursuing truth, shouldn’t we be looking for the best explanation for a  physical event—whether natural or supernatural—and not necessarily the best natural explanation?

In the movie version of Dr. Seuss’s Horton Hears a Who, the kangaroo insists that Horton the elephant is wrong about life on a tiny speck of dust. Exasperated at Horton’s belief in such small persons, the kangaroo pontificates in a naturalistic sort of way: “If you can’t see, hear, or feel something , it doesn’t exist !” Scientism declares that we can only know  through scientific observation.4 But notice: this is a philosophical assumption; it is not the result of scientific observation or research. It is a statement about science, not a statement of science. But how does one actually know that science alone yields knowledge? Or to put it another way: how can you scientifically prove that all knowledge must be scientifically provable? The “always prove it scientifically” demand is a self-contradictory one.

Let us shift things a bit to what knowledge itself is. Cutting through a good deal of debate, we can say that knowledge has three components: it is (1) a belief that is (2) true and (3) has warrant (or, others might say, justification): warranted true belief. Now, essential to knowledge is that a belief be true. So I cannot rightly say, “I know that the earth is flat” or “I know that circles are square.” You can believe false propositions or statements, but you cannot know them. Truth is bound up with knowledge. Furthermore, knowledge requires that a true belief have warrant—or something that turns a true belief into knowledge. To have an accidentally true belief is not knowledge. To have a lucky hunch that turns out to be true is not knowledge. Or let us say you conclude that it is 2:12 by looking at a clock in a store window; it turns out that you are correct, but only coincidentally: in actuality, the clock is not working! The belief that it is 2:12 in this case does not count as knowledge either.

Now since the time of René Descartes (1596-1650), a highly-rigorous but pernicious definition of knowledge has come to infect the modern mind—namely, that knowledge requires 100 percent certainty.5  So if it is “logically possible” that you could be wrong , then you do not really know. So many people turn out to be so tentative about what can rightly be called “knowledge.” But following such a rigid, absolute standard is silliness. Indeed, no one but God could live up to it! But no credible epistemologist (a philosopher who specializes in the study of knowledge) accepts this “100 percent knowledge” myth.  One major reason for that is this: you cannot know with 100 percent certainty that knowledge requires 100 percent certainty. Furthermore, we can truly know lots of things that do not rise to this level of absolute confidence. For example, you know that a world independent of your mind exists—even though it is logically possible it is just an illusion—maya, as the Advaita Vedanta Hindu would call it. So let us say that this logical possibility bumps down the “certainty level” to 97 percent. Does this mean you cannot really know that the external world exists? Well, how does the “100 percenter” know that we cannot really know the world outside our minds exists ? The fact is, we know a lot of things with confidence, even if not with complete certainty. Indeed, there would be precious little we could know if we followed that demanding standard.

When it comes to the knowledge of God’s existence, the theist does not have to live up to Descartes’ absolute standards. The believer can have plenty of good reasons for belief in God—even if not absolute, mathematically certain ones. A helpful way to make a reasoned case for God’s existence is to ask: which context makes the best sense of important  features of the universe and of human existence? For example, we are aware of the existence of consciousness, free will or a presumed personal responsibility, personhood, rationality, duties, and human value—not to mention the beginning, fine-tuning, and beauties of the universe. These are hardly surprising if a good, personal, conscious, rational, creative, powerful, and wise God exists. However, these phenomena are quite startling or shocking  if they are the result of deterministic, valueless, non-conscious, unguided, non-rational material processes. We have every reason to think a naturalistic world would not yield these phenomena—though not so with theism—and many naturalists themselves register surprise and even astonishment that such features should appear in a materialistic, deterministic universe.6

Theism, Atheism, and Agnosticism

A number of years ago, I was speaking at an open forum at Worcester Polytechnic Institute (Massachusetts). After I completed my lecture, one student stood up and confidently proclaimed: “The reason I’m an atheist is that there aren’t any good reasons to believe in God.” I told him, “You should be an agnostic then. After all, it’s possible that God exists even if no good reasons for his existence are available to us.” I then proceeded to ask what kind of agnostic he was.

This brings us to our second set of terms to clarify—theism, atheism, and agnosticism—and we should also tackle the question of who bears the burden of proof in the face of these conflicting views.

No doubt about it, the theist makes a truth claim in asserting that God exists—a maximally great, worship-worthy being. So the theist, who makes a claim to know something, should bear a burden of proof. How is this belief justified? But does this mean that the atheist and agnostic are not making a claim? This would be an incorrect assumption.

Let us consider the atheist for a moment. Michael Scriven, a self-proclaimed atheist philosopher, has actually mislabeled himself. He insists: “We need not have a proof that God does not exist in order to justify atheism. Atheism is obligatory in the absence of any evidence for God’s existence.”7 He adds that the concept of God and the notion of Santa Claus equally share the status of being “unreal” because there is no evidence for either of them.8

There are at least five problems with Scriven’s claims. The first is that he has incorrectly defined atheism. The late prominent philosopher Antony Flew—an atheist who came to believe in God toward the end of his life—defined atheism as “rejection of belief in God.”9 Then there’s the Encyclopedia  of Philosophy (1967), which defines an “atheist” as one who “maintains that there is no God, that is, that the sentence ‘God exists’ expresses a false proposition.”10 Atheist philosopher Julian Baggini defines atheism as “the belief that there is no God or gods.”11 The fact is, the standard definition of atheism is the rejection of belief in God/gods. The implication is clear: if atheism makes the knowledge-claim that God does not exist, this stance is in just as much need of justification as the theist’s claim, God exists. Both bear the burden of proof since both make claims.

Second, Scriven’s description does not allow for any distinction between atheism and agnosticism. So what is the difference? The agnostic does not know whether God exists or not. Let’s say the agnostic believes that evidence for God is completely lacking and that the evidence favoring atheism is also completely lacking . Why not take the opposite tack of Scriven here? Why not say instead that, in the absence of evidence for atheism (“God does not exist”), one should become a theist?

We could add that if both the atheist and the agnostic hold that evidence for God is lacking, how does Scriven distinguish between these two positions? According to his proposal, agnosticism would turn out to be identical to atheism. However, such a confusion of categories does not exist if we take the standard understanding of atheism as disbelief in God—not simply unbelief, which would properly describe the agnostic. Of course, an agnostic might—and typically does—say that some evidence for God does exist, but that the some, roughly equally weighty evidence against God prevents her from belief in God. But this is beside the point here. Scriven’s understanding of atheism is both uninformative and inconsistent.

Third, the absence of evidence is not evidence of absence. As I noted earlier, if evidence for God is lacking, the more logical conclusion to draw would be agnosticism. After all, it is possible that God exists even if evidence for God were nowhere to be found. In this case, we should suspend belief, which would amount to mere unbelief, but, as we have seen, that is different from disbelief ( i.e., atheism). Why think we are obligated to disbelieve?

Fourth, what if belief in God is “properly basic,” even without supporting evidence? Some Christian philosophers like Alvin Plantinga and Nicholas Wolterstorff have argued that we commonly believe many things without evidence or arguments—for example, that other minds exist or that the universe is older than fifteen minutes. Why could we not say the same about God’s existence—that it is “properly basic”? In other words, when our minds are functioning properly and directed toward the truth, then convincing or firm belief about God’s existence could simply naturally arise out of this experience. These philosophers—they are called “Reformed epistemologists”—do not deny that there is evidence for God’s existence, only that evidence is not required for belief in God to be rational.12

Now, we could claim that belief in other minds or a universe older than fifteen minutes is just part of our commonsense, everyday experience and thus is itself evidence. So such basic experiences serve as evidence, even if this evidence has not been produced through rock-solid formal arguments. But if these Reformed epistemologists are correct, then we can speak of a warranted belief in God without argument or evidence.

Fifth, to claim God and Santa Claus are on the same level is a flawed comparison. We have strong evidence that Santa Claus does not exist. We know where Christmas gifts come from. We know that humans—let alone, elves—do not live at the North Pole. We can be pretty confident that a human Santa, if he existed, would be mortal rather than ageless and undying. This is evidence against Santa. By contrast, we do have evidence for God’s existence—the beginning and fine-tuning of the universe, consciousness, rationality, beauty, human dignity and worth, and free will. The evidence for God is on a different level altogether.

In light of these points, we should bring in another important distinction. There are two kinds of agnostic: (1) the ordinary agnostic, who says, “I would really like to know whether God exists or not, but I do not have enough to go on” and (2) the ornery (!) agnostic, who says, “I do not know whether God exists or not—and you cannot know either.” The latter—the hard-nosed or militant agnostic—makes the sweeping claim that no one can know God exists. Notice that the militant agnostic is also making a knowledge-claim. Again, it stands in just as much need of justification as that of the atheist’s or the theist’s respective claims. While this brand of agnostic may not know God exists, why insist that no one else can know? What if God reveals himself in a powerful, though private, way to someone—say, at a burning bush or in a vision in her bedroom? Even if the evidence for such encounters is not publicly accessible to the hard-nosed agnostic, the theist persuaded about God’s existence through such encounters is warranted in that belief, and the agnostic could not fairly rule out such possibilities.

As mentioned earlier, evidence for God’s existence is widely available through creation, conscience, rationality and human experience. What is more, the biblical faith—unlike other traditional religions—is checkable; it opens itself up to public scrutiny. If, for example, Christ has not been raised from the dead, the Christian faith would be false, Paul argues in 1 Corinthians 15. Indeed, the Scriptures routinely emphasize the role of eyewitnesses, the importance of public signs and wonders to prompt belief (Jn. 20:30-31), and other historical evidences for all to consider.

While we can have rational reasons for belief in God, let us not forget ample practical or existential reasons for considering God. That is, the fulfillment of our deepest human longings is found in God. This is a theistic support the skeptic frequently overlooks. Our longing for identity, security, and significance, our desire for immortality and hope beyond the grave, our seeking forgiveness of our guilt and the removal of shame, or our longing for cosmic justice—all of these yearnings are fulfilled by God in Christ, who has placed eternity in our hearts (Ecc. 3:11). If we are made for a filial relationship with God, why should such longings be discounted? What is wrong with significance and security or overcoming the fear of death? Actually, we would be wise to consider these reasons—in additional to rational reasons—since we bear God’s image, which goes beyond mere human rational experience to a broad array of perfectly proper considerations.

Faith and Evidence, Knowledge, and Ignorance

Where then does this leave the ordinary agnostic? Here we must make further distinctions. “Is the ordinary agnostic innocent in his ignorance of God, or is his a culpable ignorance?” When I was in Moscow back in 2002, I took a picture of the “changing of the guard” at the tomb of the unknown soldier at the Kremlin wall. To do so, I stepped on the grass, and, knowing sufficient Russian, I saw no posted signs prohibiting my doing so. But a security guard whisked me away from the scene, insisting that I had done something terribly wrong—and probably hoping for a bribe. After asking me about my formal education, he exclaimed, “you’re a philosopher, and you do not know you shouldn’t step on the grass?” This truly was a case of innocent ignorance on my part.

Now what if I am speeding down the highway but not paying attention to the signs? If the highway patrol stops me, I could not say, “I am innocent; I did not seen the sign.” My ignorance would be culpable since I have an obligation to pay attention to speed limit signs. I am afraid many people who claim ignorance about God’s existence are more like apatheists, who do not care whether God exists. Sadly, they devote their lives to all kinds of pursuits—Facebook,  movie- watching , luxury cruises, golfing—but do not devote their mental powers to seriously contemplate the most significant  question of all, namely, God’s existence. Why should God reveal himself to the morally and spiritually lazy and apathetic?

And why should he reveal himself to the proud and arrogant, who demand that God “prove himself” through divine pyrotechnics (Mt. 16:4)? Would that really produce genuine conversion and deep love for God ? After all, the Israelites had plenty of signs—the ten plagues, the parted Red Sea, manna every morning, the constant presence of a pillar of cloud by day and fire by night. Yet most of the Israelites died in unbelief after displays of idolatry, rebellion, and murmuring (1 Cor. 10:1-13). Evidence—even a person’s rising from the dead—does not guarantee trust in God (Lk. 16:31).  God is interested in more than our justified true belief that he exists. Even the demons are solid monotheists (Jas. 2:19). The more pressing question is: are we willing to know and be known by God, to submit to God as the Cosmic Authority?

To seek God with all our heart is fundamental to God’s revealing himself to us (Jer. 29:13). As the philosopher Blaise Pascal put it:

willing to appear openly to those who seek Him with all their heart, and to be hidden from those who flee from Him with all their heart, He so regulates the knowledge of Himself that He has given signs of Himself, visible to those who seek Him, and not to those who seek Him not. There is enough light for those who only desire to see, and enough obscurity for those who have a contrary disposition.13

Beyond this, God may have certain reasons for veiling himself—to encourage greater trust and perseverance, deepened character, and so on. He reveals himself on his own terms.

Summary Thoughts

In matters theistic, atheistic, and agnostic, we should be careful to define our terms. This includes an awareness of what counts for knowledge and ignorance. We have seen that atheism—the belief that God does not exist—is not the default position. The atheist, theist, and hard-nosed agnostic each make a claim, and this claim must be justified rather than assumed. Each bears the burden of proof—not just the theist. And even the ordinary agnostic may simply be an  “apatheist”  and thus would be culpably ignorant.  Evidence is available and God is willing to reveal himself, but evidence—without humility of heart—will not yield the genuine trust and commitment God desires.


1 Richard Dawkins, River Out of Eden: A Darwinian View of Life (New York: BasicBooks,
1995), 33.
2 Del Ratzsch, Philosophy of Science (Downers Grove, IL: InterVarsity Press, 1986), 15.
3 Craig Keener, Miracles, 2 vols. (Grand Rapids: Baker Academic, 2011). For further
documented miracle accounts, see chapter 7 in J.P. Moreland, Kingdom Triangle (Grand
Rapids: Zondervan, 2007)
4 Scientism’s weaker version says that science is the best way to know, but it is usually articulated in the stronger version.
5 Descartes’ criteria for a belief-acceptance are “self-evident,” “incorrigible,” and “evident to the senses.” Of course, these criteria are not self-evident, incorrigible, nor evident to the senses.
6 For more on this, see Paul Copan, “The Naturalists Are Declaring the Glory of God:
Discovering Natural Theology in the Unlikeliest Places,” in Philosophy and the Christian Worldview: Analysis, Assessment and Development, eds. David Werther & Mark D. Linville (New York: Continuum, 2012), 50-70; Paul Copan and Paul K . Moser, The Rationality of Belief (London: Routledge, 2003); Paul Copan, Loving Wisdom: Christian Philosophy of Religion (St. Louis: Chalice Press, 2007); William Lane Craig and J.P. Moreland, eds., The Blackwell Companion to Natural Theology (Oxford: Blackwell, 2012).
7 Michael Scriven, Primary Philosophy (New York: McGraw-Hill, 1966), 102.
8 Ibid., 103.
9  Antony Flew, Dictionary of Philosophy (New York: Macmillan, 1979), 28.
10 Paul Edwards, ed., “Atheism,” Encyclopedia of Philosophy (New York: Macmillan, 1967),
1:175.
11 Julian Baggini, Atheism: A Very Short Introduction (Oxford: Oxford University Press,
2003), 3.
12 For a discussion, see Alvin Plantinga, “Reason and Belief in God,” in Alvin Plantinga and
Nicholas Wolterstorff, eds., Faith and Rationality (Notre Dame: University Press, 1983), 27.
13 Pensées (Eng. Thoughts), #430.

[Editor’s Note: Atheism image from Jan Matejko’s Stańczyk, 1862, found at  Wikipedia Commons.]