Is there any evidence for the existence of God? I need real, testable evidence.
James Stump: That is a reasonable question, but we have been fundamentally misled by the success of scientific investigation into thinking the tools of science are the best way to answer any question.
If God were just another object within the world that we wanted to know whether it exists — like Bigfoot, Atlantis or phlogiston — then the demand for “real, testable evidence” would be appropriate. And then, we ought to base our beliefs on the results of such tests. But God is not one (possible) object among other things in the world. God transcends our world and experience and, hence, lies outside the purview of scientific investigation.
This can be tricky to understand and there are several common ways of trying to explain it. One way is to say that God does not exist (the way other things might exist), but rather God is existence itself.
We might think of it like this (which is inspired by one of the greatest Christian thinkers of all time, Thomas Aquinas): say you’re looking at a couple of people playing pool, and one of them strikes the cue ball, which strikes another ball, sinking it into the corner pocket. We could focus on the chain of causes: one thing happens, then another, then another. Play the entire sequence of causes backward and eventually, you’d have to come to a first cause — something that started the chain of causes, but which itself is uncaused.
Some people find this persuasive that there had to be a god-like being to start everything up, otherwise, we have an infinite regress of causes. But all that does is get you a first domino. It says nothing about whether that first cause is still around today or has any bearing on our lives. And it wasn’t the point Aquinas was making.
Instead of looking at the pool table and asking the scientific questions “how” or “when”, ask instead the question “why?” Why does the billiard ball exist? Aquinas would say the billiard ball only exists because there is a game of billiards. The game is the ball’s “ground of being.”
If there were no game of billiards, there would be no billiard ball. And then the game itself exists only because of something else, namely the people who invented it. And these people only exist because their being also derives from something else. The existence of all these things depends on something else. So again, we get an infinite regress.
There must be something that stops this chain of dependencies. And that is God who is being itself, not derived from or dependent on anything else. Aquinas said, “All beings apart from God are not their own being, but are beings by participation” (Summa Theologica I.44.1).
That is not scientifically testable evidence for the existence of God. Rather, it aims to show that there must be something beyond the realm in which science applies, something which makes possible all of our experience. In that sense, God is not just the first domino that started the chain of causes, but God continues to sustain all things as the ground of their existence.
This is an abstract argument and not what the questioner was looking for. But I think it shows that question itself makes a category mistake — it’s like asking “What color is Thursday?” Thursday is not the kind of thing that has a color. God is not a thing that (possibly) exists in the realm describable by science. Instead, God is what makes that realm of things possible in the first place.
Now, this is not at all to say that our experience is irrelevant to our beliefs about God. But what it does is to flip the order of the relationship between our experiences and our belief in God.
Many people, like those asking the original question, seem to think that our experiences ought to serve as the ground for belief in God. If that’s the case and it’s as straightforward as that, it is curious at least that not everyone comes to the same conclusion. I’m suggesting instead that it works the other way: that God serves as the ground for how we experience things. This means that we interpret our experience in light of belief in God.
Think of interpreting as “seeing as” rather than merely “seeing that”. For example, two people might look through the same microscope and see very different things. One person might just see a bunch of blobs, while a trained professional might see that same visual data “as” cancer cells because she has been trained to see things that way.
This also applies to broader experience. The book of James in the New Testament begins with: “Consider it pure joy whenever you face trials of many kinds because you know that the testing of your faith develops perseverance” (James 1:2-3). James is reminding his audience that we can see difficulties “as” something more than just awful things with no purpose because of other things we know.
Furthermore, I look at the story of Jesus and I see it “as” the story of God becoming flesh, showing us how to live, dying for our sins and resurrecting from death to eternal life. That is an interpretation of the evidence, to be sure, and not everyone interprets the evidence in the same way. But the evidence can reasonably be interpreted that way.
This approach accords very well with what C.S. Lewis said: “I believe in Christianity as I believe that the Sun has risen, not only because I see it but because by it, I see everything else” (from “Is Theology Poetry?” in The Weight of Glory).
God is the light by which we see and make sense of other things. The more things which are seen in that light and make sense, the more plausible is the belief I bring to that experience.
So, God is not an object to be tested or experimented on. Rather, God is the ground of all being and existence. And when I look at the world in the light of Christian theism, it helps to make sense of my experience. That is not testable, scientific, evidence that forces me to believe. But it does provide support that my beliefs are reasonable.
Jim Stump is the vice president of BioLogos, where he oversees an editorial team, participates in strategic planning and hosts the Language of God podcast. Stump, an author of four books, holds a Ph.D. in philosophy and formerly served as a professor and academic administrator.
William Lane Craig: As a professional philosopher, I’m convinced that there are several good, deductive arguments for God’s existence.
By a “good” argument, I mean an argument (i) which has true premises, (ii) whose conclusion follows from the premises by the rules of logic, and (iii) which has premises that in light of the evidence are more plausible than their opposites.
In the limits of this answer, I can only outline some arguments and then refer you to resources where the premises are defended more fully.
1. God is the best explanation of why anything at all exists (aka cosmological argument):
- Everything that exists has an explanation of its existence, either in the necessity of its own nature or in an external cause.
- If the universe has an explanation of its existence, that explanation is a transcendent, personal cause.
- The universe exists.
- Therefore, the explanation of the universe’s existence is a transcendent, personal cause.
Premise (A) seems quite plausible. Imagine that you’re walking through the woods and come upon a ball lying on the ground. You would find quite bizarre the claim that the ball just exists inexplicably; and increasing the size of the ball, even until it becomes co-extensive with the cosmos, would do nothing to eliminate the need for an explanation of its existence.
Premise (B) might at first appear controversial, but it is in fact logically equivalent to the standard atheist claim that if God does not exist, then the universe has no explanation of its existence. Premise (C) is obvious. Together they imply the existence of a being which exists by a necessity of its own nature and explains why everything else exists.
2. God is the best explanation for the origin of the universe (aka kalām cosmological argument):
- Everything that begins to exist has a cause.
- The universe began to exist.
- Therefore, the universe has a cause.
Premise (A) seems undeniable. Premise (B) is supported both by philosophical arguments against the possibility of an infinite regress of events into the past and by the evidence of contemporary cosmology, specifically the expansion of the universe and the thermodynamic properties of the universe, which imply an absolute beginning around 14 billion years ago. The argument yields a cause of the universe which is plausibly beginningless, uncaused, timeless, spaceless, immaterial, enormously powerful, and personal.
3. God is the best explanation of the fine-tuning of the universe for intelligent life (aka teleological argument):
- The fine-tuning of the universe is due to either physical necessity, chance, or design.
- It is not due to physical necessity or chance.
- Therefore, it is due to design.
The fundamental constants and quantities of the universe are fine-tuned to an incomprehensible precision and delicacy, which permits the existence of embodied, conscious agents in the universe. Neither physical necessity nor chance (not even the Multiverse hypothesis) provides a plausible explanation of this remarkable fine-tuning. It follows that the best explanation is design.
4. God is the best explanation of objective moral values in the world (aka axiological or moral argument):
- If God does not exist, objective moral values do not exist.
- Objective moral values do exist.
- Therefore, God exists.
By objective values, we mean values which are valid independent of human opinion. A good many atheists and theists alike concur with premise (A). Premise (B) might seem more disputable, but it will probably come as a surprise to most laymen to learn that (B) is widely accepted among philosophers. For any argument against objective morals will tend to be based on premises that are less evident than the reality of moral values themselves, as apprehended in our moral experience. It follows logically that God exists.
5. If God’s existence is even possible, then God exists (aka ontological argument):
- It is possible that a maximally great being (a being which is all-powerful, all-knowing, and all-good, in every logically possible world) exists.
- If it is possible that a maximally great being exists, then a maximally great being exists in some possible world.
- If a maximally great being exists in some possible world, then it exists in every possible world.
- If a maximally great being exists in every possible world, then it exists in the actual world.
- Therefore, a maximally great being exists in the actual world.
- Therefore, a maximally great being exists.
It might come as a surprise to learn that steps (B)-(F) are relatively uncontroversial. Most philosophers would agree that if God’s existence is even possible, then He must exist. So the question is: is God’s existence possible? What do you think?
William Lane Craig is a renowned Christian apologist and philosopher who has authored and edited over 30 books. He is a research professor of philosophy at Talbot School of Theology at Biola University and professor of philosophy at Houston Baptist University.