One has to believe that so many fortuitous and extraordinarily improbable events, including, but not limited to, just the right genetic mutations, had to occur in just the right sequence to give rise to the millions of incredible structures we see in both the plant and animal kingdoms. A fascinating example of this is the wonderful structure and function of the elephant's trunk as the 8 minute video below illustrates.
Some would argue that just because I (and increasing numbers of scientists and philosophers) find the naturalistic explanation of the evolution of the elephant's trunk literally incredible is no argument against the claim that it actually did evolve. The naturalist scoffs at skepticism based on incredulity, calling it, as does Richard Dawkins, the "Argument from Personal Incredulity," insisting that such reasoning is extremely weak.
As philosopher William Lane Craig points out, however, the argument is actually quite sound. He formulates the "Principle of Personal Incredulity" (PPI) this way:
PPI: We should believe something that we find incredible only if we are aware of overwhelming evidence in its favor.This is a perfectly reasonable principle, and indeed it's one that even underlies much of the atheism of our day. Whatever arguments atheists might adduce to justify their lack of theistic belief many of them actually reduce to the fact that the atheist finds the existence of a supernatural mind quite literally incredible.
The problem for the atheist, however, is that there's a great deal of evidence in favor of the existence of God and very little against it whereas there's scant evidence that natural selection coupled with genetic mutation, unaided by a purposeful mind, could produce something like the elephant's trunk.
Watch the video and see what you think: