In one of my previous posts, I argued belief in God is rational, not provable. In fact, I believe that belief in God is more reasonable than disbelief given the evidence. This evidence is a cumulative case for the existence of God, not just one silver bullet argument. Instead, the arguments for the existence of God are more like a chain-link fence, stronger together than the parts are apart.
So is belief in God actually rational? The first link to build our fence is the Kalam Cosmological argument. This argument has been popularized recently by William Lane Craig. In logical form the argument goes like this:
1. 1. Everything that begins to exist has a cause
2. 2. The universe began to exist
3. 3. Therefore, the universe has a cause
The conclusion clearly follows from the premises. Therefore, if the premises are true, then the conclusion is sound.
But are the premises true?
Does Everything that Begins to Exist Have a Cause?
There are only two options for premise 1. First, everything that begins to exist has a cause, or there are some things that begin to exist which do not have a cause. But what would an uncaused beginning look like? Can you think of anything that has begun which did not have a cause? I can’t. In fact, it seems as though it is a brute fact, that things which begin to exist are caused.
There is only one major objection to this premise. Often, atheists will point to quantum physics as examples of things coming into existence uncaused or without reason.
I will admit quantum mechanics are very weird, but there is no evidence to suggest there is absolutely no cause for the things we observe in the quantum world. Energy fluctuations and other reasons for the causes of the quantum physical world are not only possible, but considering our limited knowledge of the quantum they are probable. In addition, quantum mechanics is still an unreliable source of any kind of information. It seems to be clutching at straws to appeal to this “science.”
So, the first premise seems to be true. Everything that begins to exist has a cause.
What about premise two?
How do we know if the universe began to exist?
There are two lines of evidence showing a beginning of the universe, Scientific and Philosophical. We will focus on the Scientific.
The Big Bang Theory. Virtually all astronomers and physicists now agree with the Big Bang Theory. Scientists have observed many lines of evidence for a Big Bang. Among these are the fact that the universe is expanding (which means it will get smaller if we went back in time), and the correct amount of background radiation consistent with what might have happened in an explosion at the beginning of the universe.
Also, the 2nd law of thermodynamics suggest the universe began to exist at some point. This law states any closed system will use up energy and eventually die a “heat death.” At this point in time we have not yet run out of energy, meaning there is still energy to use. This shows us the universe cannot be eternal. If it was eternal, the universe would have gone through an infinite amount of time to reach the current point in time. This means the universe would have run out of energy. However, because we haven’t run out of energy, this means there has not yet been enough time to use it all up, suggesting a starting point.
Now, one objection to this evidence from the 2nd law of thermodynamics is to speculate the universe might not be a closed system. If this was the case, then the universe could draw upon an outside force for more energy. However, there is no compelling reason to believe in such an outside force feeding the universe, and if it was true, this “source” would be dangerously close to the definition of God, being before time, spaceless, immaterial, powerful, etc. Also, the above evidence for the Big Bang, is suggestive to reach the simplest conclusion about energy in the universe, which is that energy is being used up.
These lines of evidence, and others, are suggestive to believing the universe did have a beginning.
But what does that prove?
The Universe Had a Cause
The above premises logically lead to the conclusion, the universe had a cause. Does this prove God? Could the cause be something other than God? It could, but one must remember this cause must be timeless, spaceless, immaterial, powerful, etc. These qualities are much like the definition of God of the Bible. We do not yet know if the God of the Bible is the cause of the universe, but whatever the cause, it is consistent with this definition of God.
This argument does not prove the existence of God 100%, but it is good evidence leading to that conclusion. If we can find other, independent lines of evidence, we can make the case even stronger.