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Philosophical arguments for God


Why think God exists? Skeptics often demand that theists need to conclusively prove that God is there before either of us can believe He is there. But just because I may not be able to convince a skeptic that God exists doesn’t mean I cannot know God exists. God can reveal Himself to people in numerous ways, some of which don’t involve arguments. For instance, the Spirit Himself testifies to Christians’ spirits that we are God’s children (Romans 8:16). And God can also withdraw knowledge of Himself (Romans 1:18–32). I don’t have to be a master debater for God to reveal himself to me sufficiently to know that He exists. See Agnosticism for more information.

In fact, there is no such thing as a ‘conclusive proof’, if by this one means an argument that compels universal acceptance. No argument can make people believe its conclusion. Humans are not logic-chopping robots; they come with biases, experiences, and tastes that affect the way they view arguments. For instance, consider the contrast between C.S. Lewis, a former atheist who later embraced idealistic philosophy, and Antony Flew, a hard-nosed evidentialist philosopher. Lewis was convinced by the moral argument for God, which shows God to be the moral ideal: “it is more important that Heaven should exist than that any of us should reach it.”1 Flew rejected Lewis’ moral argument for God, although late in life he was convinced of deism by the argument from design. He adopted a ‘convince me with hard evidence’ stand (a position he apparently never abandoned).

But if there are no conclusive proofs for God (in the above sense), what use are arguments for God? If an argument is sound and solid, it acts as a sign pointing to God. But signs only convey limited information, and people looking at a sign need to properly read and respond to the sign. A person who ignores a stop sign, or misreads a speed limit sign, will act accordingly. Their response may even have disastrous consequences. But that’s hardly the fault of the sign! In the same way, good arguments for God don’t have to tell us everything about God. Nor can we make people read and respond to them properly. All they offer is a public case commending belief in God as reasonable. And all we can do is faithfully portray the signs. We plant and water, but only God can give the increase (1 Cor. 3:7).

As such, when reading these arguments below, it must be understood that they are offered in that very spirit. They are not conclusive proofs, but signs pointing to God, showing at the very least that belief in Him is reasonable, if not rationally obligatory.

Moral argument: Can we be good without God?


Moral values and duties impress themselves upon us every day. For instance, practically everyone knows that torturing babies just for fun is objectively bad, and compassion for the helpless is objectively good. And we readily recognize those who disagree as abnormal (e.g. sociopaths). But why? What makes the world a moral world? The best explanation is God. God is the ultimate standard of goodness, and all morality is measured by His character, and meted out to us by His commands. Nothing else, whether evolution, or finite persons, or even moral facts themselves, provide a sufficient ground for moral values, duties, and accountability. We can formalize this argument like this:

  1. If God does not exist, objective morals do not exist.
  2. Objective morals exist.
  3. Therefore, God exists.

For more on this argument, please see:

Kalām cosmological argument: In the beginning …

In the beginning … what? Genesis 1:1 says “In the beginning God created the heavens and the earth”, but why think that’s true? First, nothing comes into being without a cause, a basic principle of science and rationality. Everything we see that started to be has some sort of cause. But we also know that the universe itself had a beginning. The laws of thermodynamics powerfully imply that the universe had a beginning. And an infinite regress of secondary causes can’t even exist, because it can be shown mathematically that this would lead to absurdities! But that means the universe itself had a cause. But what could cause the universe? The universe is all of space-time-matter reality, so the cause can’t be bound by those things. And it must be powerful to cause the universe! The simplest solution is an eternal, non-material, uncaused cause. But how to get a temporal effect from an eternal cause? That cause must have freely chosen to create, so it must be a personal cause. So the simplest cause for the universe is a single, powerful, personal, eternal, immaterial, uncaused cause—it sounds a lot like God! We can formalize the argument like this:

  1. Everything that has a beginning has a cause.
  2. The universe had a beginning.
  3. Therefore, the universe had a cause.

For more on this argument, please see:

Contingency argument: Why is there something rather than nothing?

Why is there something rather than nothing? Underlying the question is a principle: everything has a reason why it exists. What sort of reasons could they be? It turns out there are really only two basic sorts. A thing might be caused by something else, or it might be such that it must exist by its own nature.

But could the universe be exempt from needing a reason for why it exists? If so, why should it be exempted? Size doesn’t matter. If we replaced the universe with a universe-sized book, the book would still need a reason for why it is there. Therefore, so does the universe. And if we exempt the universe, there’s no reason not to exempt other things as well, such as things in the universe. But no sane person believes that ducks, stars, and chairs could exist for no reason. And imagine what would happen to science if we adopted this principle. Science is all about finding explanations for things. So if some things have no explanation, how could we know whether science applies to them or not? We wouldn’t be able to do science at all! So much for atheism being the friend of science.

So then, why does the universe exist? It clearly doesn’t have to exist. It’s comprised of things that don’t have to exist! Any number of universes, or none at all, could have existed instead. And yet it does exist. So, if there’s a reason why the universe exists, what would it be? God made it.

But notice I said: ‘if the universe has a reason why it exists, that reason is God’. Atheists will often respond: ‘But if atheism is true, the universe doesn’t have a reason why it exists.’ That’s precisely the point! If they say ‘if atheism is true, there’s no reason why the universe exists’, it’s also true that ‘if the universe has a reason why it exists, atheism is false’. And why would atheism be false if there’s a reason why the universe exists? Simple: God is the reason, if it has one.2

But if everything has a reason why it exists, and the reason why the universe exists is that God made it, then God exists. The ultimate answer to why there is something rather than nothing is God. We can summarize this as follows:

  1. Everything has a reason why it exists—either by the necessity of its own nature, or because it was caused by something else.
  2. If the universe has a reason why it exists, it is that God caused it to exist.
  3. The universe exists.
  4. Therefore, God caused the universe to exist.
  5. Therefore, God exists.3

Design argument: Usefulness of math in science

Why is mathematics such a useful tool in science? It’s as if nature is written in the language of math. It seems like a massive fluke!4 At least, apart from God.


But is it really likely that the usefulness of math in science is just dumb luck apart from God’s existence? After all, it’s very hard to imagine a self-consistent world without basic mathematics applying (e.g. 2+3=5). But it’s not basic math that make the link between math and science look like a coincidence. Rather, it’s complex mathematical ideas like imaginary numbers, tensor calculus, and Hilbert space. Many of these ideas have no physical existence (such as Hilbert space). But they are vital for describing how nature works. Even if the physical world must be mathematical, that doesn’t explain why the particular complex math we use works in describing the physical world.

Could mathematical structures cause the physical world? Only if they could cause things to be. But does e.g. the object ‘5’ cause it to be true that my hand has 5 digits? That doesn’t even make sense! The number ‘5’ describes how many digits are on my left hand; it doesn’t cause that fact to be true. If they exist at all, mathematical objects don’t cause anything.

But instead, might the universe actually be a mathematical structure? Physicist Max Tegmark believes just this.5 But he also provides us with powerful reason to reject his view:

This crazy-sounding belief of mine … makes us self-aware parts of a giant mathematical object. … [T]his ultimately demotes familiar notions such as randomness, complexity and even change to the status of illusions … 5

Tegmark’s belief sounds crazy because it is crazy. It forces us to regard almost everything basic to human experience as an illusion! Any argument for this will always have premises less convincing than our conviction that our experiences are real. Better to believe a much less ambitious and counter-intuitive idea: that the universe was structured so mathematical concepts would be useful in describing it. At least that doesn’t mean we live in a mathematical Matrix! In essence, even if mathematical objects are real, they can’t explain by themselves why nature is written in the language of maths.

But what if mathematical structures don’t exist? Apart from God, the problem is even worse. The usefulness of math in science is something we discovered. We didn’t invent it! Nature really is written in the language of math regardless of us. But if mathematical objects can’t explain it, and we can’t explain it, and it’s not a coincidence, then why is nature written in the language of math? A transcendent mind. In other words, God. We can summarize the argument like this:

  1. If God does not exist, the applicability of math to the physical world is just a coincidence.
  2. The applicability of math to the physical world is not just a coincidence.
  3. Therefore, God exists.6

This is just one of many different design arguments. Some focus on the fine tuning of the universe for life, or the origin of life, or the origin of biological structures, or the origin of consciousness. See Created or evolved? for an overview. On creation.com, you will find many examples of design in nature that point to the God of the Bible.

Ontological argument: God is uniquely supreme

Ever since Anselm of Canterbury first put forward his version in the 11th century, ontological arguments have been the source of much discussion and debate. They rest on two basic ideas. The first comes from Anselm himself—God is ‘that than which nothing greater can be conceived’. In other words, by definition there’s nothing conceivably equal to or greater than God. The second is that if it’s possible that God exists, He must exist. God can’t just happen to exist, because part of what ‘God’ means is a necessarily-existent being. So either God must exist, or He can’t exist.

So, what do these arguments look like? Here is an example:

  1. ‘That than which nothing equal to or greater can be conceived’ (i.e. God) possibly exists. (Premise)
  2. Suppose that God can fail to exist. (Supposition)
  3. A being that cannot fail to exist is greater than a being that can fail to exist. (Premise)
  4. If ‘that than which nothing equal to or greater can be conceived’ can fail to exist, then it is not ‘that than which nothing equal to or greater can be conceived’ (from (3)).
  5. But this is a contradiction.
  6. Therefore, ‘that than which nothing equal to or greater can be conceived’, i.e. God, cannot fail to exist.

What does all this mean? First, posit that God possibly exists. Then, suppose that God doesn’t exist. But what does it mean for there to be nothing conceivably greater than or equal to God? Think about how things can exist. A thing either can’t fail to exist (i.e. it exists necessarily), or it can fail to exist (i.e. it exists contingently). Which is better? Necessary existence, right? Now apply this to God. If there’s nothing conceivably greater than or equal to God, can He fail to exist? Clearly not. Why? If He could, then God could not be ‘that than which nothing greater or equal to can be conceived’. But that’s just nonsense! There’s nothing conceivably greater than or equal to God by definition. Therefore, supposing that God doesn’t exist makes no sense (provided that God possibly exists). Since by definition there’s nothing conceivably greater than or equal to God, if He exists, He has to exist in the greatest way possible. That is necessary existence. But if God necessarily exists, then He actually exists.

Many regard this as just a word trick. But it isn’t. The statement ‘There is nothing conceivably greater than or equal to God’ does entail that ‘God cannot fail to exist’. But the two statements don’t mean the same thing. People often think ‘God’ is a coherent concept without realizing it implies that God must exist. These arguments can help us see this. The conclusion is implicit in the premises, but that’s true for every valid deductive argument.

Critics also often say that similar arguments could be made for any so-called necessary being. In other words, they say that if something could exist necessarily, it does exist necessarily. And that’s a valid way to argue. The trick is showing that other so-called necessary beings are possible. But at most it would only show that God is not the only necessary being around. But that’s not even relevant to this version! This version uses the greatness of necessary existence (compared to contingent existence) to show that God must exist. If there are other things that must exist, God must still be greater than them.

Or the critic might say that ‘that than which nothing greater or equal to can be conceived’ is incoherent, like the idea of a ‘married bachelor’. This is probably the ‘best’ objection of the lot, because it’s the easiest to imagine. But notice what it forces the atheist to say: not simply that God doesn’t exist, but that the very idea ‘God exists’ is incoherent. Saying that is easy enough. But how to defend such a claim? That is anything but easy!

And there are reasons to think God is possible. For instance, the other arguments listed here give us reason to think that God at least possibly exists. Atheists have also tried, and failed, to find a clear-cut incoherence in the idea of God for millennia. Even the very idea of a being nothing can possibly be greater than or equal to plausibly entails its own possibility.7

Anselm thought he had found in the ontological argument a conclusive proof for God. But it’s not. It’s hard to understand. And it’s not immediately obvious that the statement ‘God does not exist’ is necessarily false. But it can help undercut doubts about God for those inclined to thinking that God possibly exists. And even for the atheist, it can help show them the intellectual cost of rejecting the possibility of God. For more on this, please see our God Questions and Answers page. See also:


Argument from miracles: Jesus’ resurrection

Jesus taught with a unique sense of divine authority. He claimed to have authority to forgive sins. He said that following Him determined one’s eternal destiny. He prophesied on His own authority (“Amen I say to you … ”). He claimed to be Lord of the Sabbath (Mark 2:27). His favourite title for himself (“the Son of Man”) also revealed that He believed Himself to be the heir of God’s eternal kingdom (having taken this term from Daniel 7:13–14)! Jesus left a distinct impression that in His very person Israel’s God was at last returning to Zion to establish His kingdom. And this was the impression He clearly left on His earliest followers, e.g. James 2:1, John 1:1, Romans 10:9–13, and Mark 6:45–53. See Is Jesus really God?

But why believe such outlandish claims? Jesus said, numerous times, that He would be killed, and then raised from the dead (e.g. Matthew 12:38–40, Mark 8:31). This is how Jesus believed God would vindicate him. The resurrection verifies His claims, if true. Jesus was supposedly raised never to die again, which is a miracle only the controller of the cosmos, i.e. God, could pull off.

But are miracles even possible? A miracle is nothing more than a historical event with a supernatural cause. And we have no problem inferring unseen entities like quarks or ancient artisans to explain observational evidence. Miracles are only problematic if we limit our pool of possible causes to natural causes before looking at the evidence. But why so constrain ourselves, especially if a supernatural cause is the best, or even only, explanation of the evidence?

So what evidence is there for Jesus’ resurrection? First, Jesus died. You can’t have a resurrection if the person didn’t die! Jesus’ death by crucifixion is better attested than pretty much any historical event in antiquity. It’s everywhere in the New Testament and the Apostolic Fathers. And it’s mentioned by Josephus, Tacitus, and Pliny the Younger, just to name a few non-Christian sources that mention it.

Second, we have a church tradition for the resurrection that dates to about three years after Jesus’ death: 1 Corinthians 15:3–8. It testifies of multiple appearances of Jesus to individuals and groups in a variety of settings. Paul wrote it about 25 years after Jesus’ death, and said of it: “I delivered to you as of first importance what I also received”. He must have received this message from the apostles he equates his message with in verse 11. And he first met these apostles about 3 years after his conversion (Galatians 1:19–20), which was about 3 or so years after Jesus’ death. See Easter’s earliest creed for more information.

Third, Jesus’ tomb was empty. All the Gospels (explicitly) and 1 Corinthians 15 (implicitly) testify to this. Even the church’s enemies presuppose this in their alternative explanation, that the disciples stole Jesus’ body (Matthew 28:11–15). Even if Matthew was putting words in his enemies’ mouths, it makes no sense to have them admit an empty tomb if the tomb wasn’t actually empty.

Fourth, the first eyewitnesses to both the empty tomb and the resurrection were women, and the church didn’t hide this. Women’s testimony was worth nothing in the 1st century, so the early Christians had every reason to leave this detail out. It makes even less sense to start a ‘plausible’ lie with women as your primary witnesses! As such, it makes no sense to consider the Gospel resurrection narratives as legends, since they all start with women witnesses.

Fifth, the disciples really believed that Jesus appeared to them risen from the dead. They were not expecting it; their leader was dead. A crucified messiah was a contradiction in terms. And there was nothing in Jewish tradition to suggest that one man would rise immortal from the dead in the middle of history. And if the claim was a lie, the apostles had to have known it. And yet most suffered for the claim, and many even died for it. Why would multiple disciples die for a lie they made up?

Finally, Paul and Jesus’ brother James believed, despite being skeptical before Jesus appeared to them. Jesus’ brothers didn’t believe in Him before his death (John 7:5), but James became a leader in the Jerusalem church, and was eventually martyred for his Christian faith because “he appeared to James” (1 Corinthians 15:7). Paul tried to destroy the church, but after having what he believed was an encounter with the risen Jesus, became its greatest missionary, and also ended up martyred. Why would skeptics lie for the church, let alone die for its central message?

No explanation can account for all these facts, as well as the context that Jesus’ claims to be God incarnate, other than God raising Jesus from the dead. And this would entail that the God who raised Jesus from the dead exists.

We can summarize this argument as follows:

  1. There are several solid facts concerning the fate of Jesus: His death by crucifixion, the empty tomb, His appearances after having died, and the disciples’ genuine belief in His resurrection.
  2. These facts are best explained by the thesis ‘God raised Jesus from the dead’.
  3. If God raised Jesus from the dead, then the God revealed by Jesus exists.
  4. Therefore, the God revealed by Jesus exists.8

For more information, please see Did Jesus Christ really rise from the dead?

More arguments for God!

These are just a few examples of arguments for God. More could be multiplied (see e.g. Does God exist? and Atheism). God has provided plenty of witness of Himself, both in creation and redemption, for faith in God to be reasonable. These arguments can help us to see how God has revealed Himself. But no amount of arguments can make people believe; God must work on people’s hearts. And God isn’t simply interested in people believing that He exists. If He was, He might have made it even more plain than it already is! But He wants us to trust and love Him through his Son. And the evidence God has provided is indeed sufficient for that.

First published: 9 August 2016
Re-featured on homepage: 13 January 2022

References and notes

  1. Lewis, C.S., Surprised by Joy, Harper Collins, London, p. 245, 2002. Return to text.
  2. But is there a reason why God exists? Yes, there is: God is naturally necessary—by His very nature He can’t fail to exist. Return to text.
  3. The form of this argument comes from Craig, W.L., On Guard, David, C. Cook, Colorado Springs, CO, p. 54, 2010. See also Kumar, S. and Sarfati, J., Christianity For Skeptics, Creation Book Publishers, Atlanta, GA, pp. 17–19, 2012. Return to text.
  4. Wigner, E., The Unreasonable Effectiveness of Mathematics in the Natural Sciences, in: Communications in Pure and Applied Mathematics 13(1), John Wiley & Sons, New York, 1960; www.dartmouth.edu/~matc/MathDrama/reading/Wigner.html. Return to text.
  5. Tegmark, M., Is the Universe Made of Math? www.scientificamerican.com, 10 January 2014. http://www.scientificamerican.com/article/is-the-universe-made-of-math-excerpt/ Return to text.
  6. For the original formulation and defense of this argument, see Craig, W.L., God and the ‘Unreasonable Effectiveness of Mathematics’, Christian Research Journal 36:31–35, 2013. Return to text.
  7. See Maydole, R.E., The ontological argument; in: Craig, W.L. (Ed.), The Blackwell Companion to Natural Theology, Kindle Locations 15314–15325, John Wiley & Sons Ltd, Chichester, United Kingdom, 2009 (Kindle edition). A helpful exposition of Maydole’s modal perfection argument can be found here: Miller, C., Robert Maydole’s Modal Perfection Argument, calumsblog.com/apologetics/arguments-for-gods-existence/modal-perfection-argument/, accessed 23 June 2016. The crucial aspect for this point is the first step of Maydole’s argument, which argues for the possibility of a supreme being (i.e. a being that nothing can be greater than or equal to). Return to text.
  8. This summary was adapted from Craig, W.L., Does God Exist? reasonablefaith.org, accessed 23 June 2016. Return to text.