Thoughts inspired by and collected from Alvin Plantiga’s Where the Conflict Really Lies:
Naturalism is the philosophical position that only natural phenomena exists. According to the naturalist, everything that we see is therefore the result of the laws of nature. Life exists as the result of unguided evolution, the gradual selection in living organisms among random genetic mutations for those mutations that make it more likely that the organism will successfully reproduce.
People in the past and present believe a great many things that are not true. If unguided evolution is true, then religion is one example- most of the people of the world believe in God or a god of some kind, and in the past this was even more true than it is today. Why did they believe these things? If unguided evolution is true, then they believed it because it provided some survival advantage. It is not necessary to even know why belief in evolution provided a survival advantage. We know it did because most people possessed the trait, and the trait would not have been so nearly universally selected unless it provided some such advantage. Belief in religion causes the believer to expend a great many resources in the pursuit of his religious belief; if it did not provide some serious advantage, such a detrimental belief would soon be bred out, as those that believe it would be less fit for survival. The normal explanation by Darwinists is that belief in religion is advantageous, or was in the past, because it encourages cooperation with others through the idea of absolute morality. But the mechanism is ultimately unimportant; we know it provided a survival advantage because otherwise it would not exist.
But here’s the problem- according to the believer in unguided evolution, belief in a God that guides everything is false. Therefore a false belief provides a survival advantage. For a belief to be evolutionarily advantageous it is not at all necessary that the belief is true, only that it provides some advantage to the survival and reproduction of the species. Friedrich Nietzche, the atheistic nihilist, expressed the consequence of this belief well when he said that there is no more unfounded assertion in all of human thought than the assertion that truth is to be preferred to falsehood. In his book Beyond Good And Evil he asserted that the only thing that is real is the will to power- not truth or falsity, good or evil.
But if he’s right and beliefs can be held by many billions of people simply because those beliefs provide survival advantages, then how can we have any confidence in any of our beliefs? In that case our minds are wired by evolutionary biology to believe things because they help us propagate, not because they are true. And that includes our belief in unguided evolution. Thus naturalism, the belief that only matter exists and all that is is the result of blind chance and natural laws, and random selection of genetic traits produced all the life that we see, renders all knowledge impossible and makes any assertion of the truth of one proposition over another a meaningless assertion.
One can repeat the same exercise with beliefs such as racism and sexism, things we Christians would agree are false. And it can be repeated ad infinitum with any number of beliefs that people held in the past. In the past they were believed because they provided a survival advantage. Therefore evolution can and very frequently does result in people being hardwired to believe false things for survival advantage, and thus unguided evolution results in minds that are hardwired to believe what helps them survive and propagate, not what is true. Natural selection ought therefore to select for people like Genghis Khan, who very successfully propagated his genes throughout Asia and Europe. And the result is the complete overthrow of any such conception as truth. Only the will to power remains.