The Existence of God 1/3: The Cosmological Argument

“In the beginning God created the heavens and the earth” (Gen 1:1).

Before we get into the theology, it’s best to stop and answer one of the biggest questions of our age: How can you believe in a deity? Over the centuries, Christians have formulated dozens of arguments to prove the existence of God. One of the oldest, and my favorite, has had a revival in modern times due to advancing scientific knowledge.

It’s called the cosmological argument. Written as a syllogism, it goes like this:

1. Everything that began to exist has a cause.
2. The universe began to exist. 
3. Therefore the universe has a cause.

For centuries the second statement was attacked. Many scientists took it as an object of faith that the universe was eternal. Then the 20th Century happened. Einstein’s Theory of General Relativity seemed to require that the universe was expanding. Then Hubble discovered that all the galaxies in the universe are moving apart from each other as if they were all the product of a massive explosion. The Big Bang theory was born. General Relativity and Big Bang cosmology have been bolstered by several discoveries since. Today, it is very difficult to deny that the universe began to exist, though there are scientists who try because of the religious implications. Even if someone doesn't believe in Big Bang cosmology, the second law of thermodynamics also requires the universe to have a finite beginning.

Since statement #2 is hard to deny,* people today will do something no one ever dreamed of before and attack statement #1. But that’s simply absurd. Nothing has ever been observed to come into existence without a cause, and there’s no reason to believe that there could be one massive exception in the universe itself.

It is important to get the first statement right. It is not “everything has a cause.” This is how atheists usually misrepresent the argument, and in that form the obvious rejoinder is “who created God?” But if only that which began to exist has a cause, there is room for something to be uncreated, eternal.

In fact, something must be eternal. If not, then something created the universe, and something else created that, and something else created that, and on forever. But an infinite progression like that is mathematically and logically impossible. So something has to be eternal, and the universe is not it.

But why does that eternal thing have to be God? Can’t it just be some kind of creative force? No. It must be a mind, a personal being.

Philosopher William Lane Craig, the man who revived the cosmological argument in the 20th Century, explains:

“If a cause is sufficient to produce its effect, then if the cause is there, the effect must be there, too. For example, water freezes when the temperature is below 0 degrees centigrade; the cause of the freezing is the temperature’s falling to 0 degrees. If the temperature has always been below 0 degrees, then any water around would be frozen from eternity. It would be impossible for the water to begin to freeze just a finite time ago. Now the cause of the universe is permanently there, since it is timeless. So why isn’t the universe permanently there as well? Why did the universe come into being only 13.7 billion years ago? ... The answer to this problem must be that the cause is a personal being with freedom of the will. His act of creating the universe is a free act that is independent of any prior conditions. ... Thus, we’re brought not merely to a transcendent cause of the universe but to its Personal Creator.”

So modern science has joined together with ancient philosophy to demonstrate that a timeless, powerful, non-physical being created the universe because he decided to. God did not have to create us. God chose to create us. We should respond to that by choosing to get to know him.


For more detail on this topic, the best place to go is the man who (re-)started it all. William Lane Craig’s On Guard: Defending Your Faith with Reason and Precision has an excellent popular level explanation of the cosmological argument among other topics.

*The universe’s beginning to exist is only necessary for this argument. If the universe were eternal, that does not disprove the existence of God. Aquinas made many arguments for the existence of God assuming the universe was eternal because it was simply too easy to prove if the universe had a beginning.

Image credit: Deshaping by Daniel Frančišković, used under Creative Commons


Part of Christianity 101