Is there any evidence that God exists?

What counts as evidence?

Evidence for God will not look like evidence for a new planet. God is not one more object inside the universe that a telescope might detect. If he exists, he is the reason there is a universe at all. So the most fitting evidence is not a gap in our scientific knowledge but the most basic features of reality: that anything exists, that it began, that it is orderly, that it can be understood.

One of the most discussed arguments, the kalam cosmological argument, has roots in early Christian and medieval Islamic philosophy (al-Ghazali) and was revived in modern form by William Lane Craig. It runs in three steps.

The argument

1. Whatever begins to exist has a cause

This is one of the most basic principles of rational thought. Things do not pop into being uncaused out of absolutely nothing. If they could, it would be inexplicable why anything and everything doesn't do so. Science itself depends on this principle: it is the search for causes.

2. The universe began to exist

Two independent lines of evidence support this premise.

• Philosophy. An actually infinite series of past events seems impossible to complete. If the past were infinite, an infinite number of days would have had to elapse before today, and we could never have arrived at today. (Philosophers continue to debate this point.)
• Cosmology. The expansion of the universe, the cosmic microwave background and the abundance of light elements all point back to a hot, dense beginning about 13.8 billion years ago. The Borde–Guth–Vilenkin theorem (2003) adds that any universe which has on average been expanding throughout its history cannot be extended infinitely into the past. The second law of thermodynamics points the same way: if the universe were infinitely old, it would long ago have run down into equilibrium.

Physicists still debate what happened at the very first moment, and some propose models that try to avoid a beginning. But the weight of current evidence fits a beginning far better than an eternal universe.

3. Therefore the universe has a cause

This is just logic: if the first two premises are true, the conclusion follows.

What kind of cause?

Because the cause brought all of space, time, matter and energy into being, it cannot itself be made of any of them. Reflecting on that gives a striking profile:

The last point deserves explanation. If the cause were a mechanical set of conditions existing eternally, its effect should be eternal too: if the conditions were always present, the effect would always be present. The best explanation for a temporal effect from a timeless cause is an agent who freely chose to create. Only two kinds of things could be immaterial and timeless: abstract objects (such as numbers), which cause nothing, or a mind.

This is what the Bible has said all along: "In the beginning, God created the heavens and the earth" (Genesis 1:1).

One thread in a larger rope

The kalam argument is not the only evidence. Others include:

• Contingency. Leibniz asked why there is something rather than nothing. Everything we observe could have failed to exist, and so needs an explanation outside itself. The chain ends in a being that exists necessarily.
• Fine-tuning. The physical constants fall within very narrow life-permitting ranges.
• The moral law. Objective moral obligations point to a moral lawgiver.
• Jesus of Nazareth. The historical evidence for his resurrection.

Each argument is like one strand in a rope. Together they make a strong cumulative case.

Why it matters

If the universe had a beginning and a Creator, then we are not cosmic accidents. Paul told the philosophers in Athens that the God who made the world is "not far from each one of us" (Acts 17:27) and that he has made himself known in a man he raised from the dead (Acts 17:31). The God who made the stars invites us to know him personally through Jesus Christ.