Here is a creationist argument for the existence of God:

1. If God exists, then it is very likely that the basic kinds of plants and animals all began to exist at the same time.

2. If there is no God, then it is very unlikely that the basic kinds of plants and animals all began to exist at the same time.

3. The basic kinds of plants and animals all began to exist at the same time.

Therefore:

4. Other things being equal, it is probable that God exists.

Here is another creationist argument for God:

5. If God exists, then it is very likely that human beings came into existence very soon after the origin of the earth and life on earth (ie. less than a thousand years later).

6. If there is no God, then it is very unlikely that human beings came into existence very soon after the origin of the earth and life on earth (i.e. less than a thousand years later).

7. Human beings came into existence very soon after the origin of the earth and life on earth (i.e. less than a thousand years later).

Therefore:

4. Other things being equal, it is probable that God exists.

These and other arguments can be summed up as follows:

8. If God exists, then it is very unlikely that human beings evolved from simple single-celled organisms over a period of billions of years.

9. If there is no God, then it is somewhat likely that human beings evolved from simple single-celled organisms over a period of billions of years.

10. It is NOT the case that human beings evolved from simple single-celled organisms over a period of billions of years.

Therefore:

4. Other things being equal, it is probable that God exists.

The creationist or anti-evolution premises in these arguments are false, so we can assert the opposite claim, and turn each of the above arguments into an argument against the existence of God. Here is the first argument modified into an argument for atheism:

1. If God exists, then it is very likely that the basic kinds of plants and animals all began to exist at the same time.

2. If there is no God, then it is very unlikely that the basic kinds of plants and animals all began to exist at the same time.

11. It is NOT the case that the basic kinds of plants and animals all began to exist at the same time.

Therefore:

12. Other things being equal, it is probable that there is no God.

One of the primary reasons or motivations behind creationism is the desire to preserve the belief that the Bible is inerrant, especially the book of Genesis. But the conflict between evolution and religion is NOT limited to a conflict over how to interpret the book of Genesis. All of the arguments for God included in Richard Swinburne’s case for God are based on suppositions about what God would be likely to do (or create) if there were a God. Swinburne’s reasons for what God would be likely to do are independent of the contents of the book of Genesis, as far as I can tell.

Swinburne accepts the theory of evolution as the best explanation for the origin of species, but it seems to me that it is much more likely, a priori, that God would instantaneously create all living things, than that God would create a physical universe that had some tendency to produce living things that would in turn have some tendency to evolve into more complex and more intelligent creatures over a period of billions of years.

In other words, even apart from the book of Genesis, the basic idea of creating all basic kinds of plants and animals at the same time makes more sense as the action of an all-knowing, all-powerful, and perfectly good person, as opposed to the very slow, halting, random, and uncertain process of evolution. If I can make a perfectly good piece of toast in just 30 seconds by using a toaster, why would I spend 50 years making a piece of toast by some other very slow, random, and uncertain process? That would be stupid.

God is the very opposite of stupid. If there is a God, then God is all-knowing, all-powerful, and perfectly good, and thus we can make reasonable educated guesses about what God would do or not do. God would not use the very slow, random, and uncertain process of evolution to bring humans into existence if he could do so in an instant. God, if God exists, is all-powerful and all-knowing, so God could bring humans into existence in an instant. Therefore, it is very likely that God would NOT use the slow, random, and uncertain process of evolution to bring human beings into existence.

The creationists appear to be correct on that point, even though Genesis does not provide a factually accurate description of the origin of species and of human beings. We do not need the book of Genesis to tell us that it makes more sense for God to create plants, animals, and humans instantly than to use the very slow and random process of evolution to bring about plants, animals, and humans.