If this is a reasonable way of thinking, then evolution is not actually irrelevant to the issue of theism vs. atheism; obviously, the pattern of life on this planet is one of the things which appears considerably more comprehensible if one assumes there's no God pulling the strings. Certainly it's hard to see why the God of any of the major religions wouldn't have done lots of meddling, and yet to all appearances life has developed over time in ways completely explicable by evolution, with no signs of meddling whatsoever. So, it seems to me that the anti-evolutionists are, kind of, right; evolution provides a reason not to believe in God (though, sadly for their cause, it provides a good reason).This is actually a fairly common line of thinking, because nature is on the whole rather overtly violent. It doesn't seem like the sort of thing that would have been build by a benevolant God of any description and the almost "cobbled together" fashion of life as we see it. Of course, even though I have a theistic belief, I still do not see how evolution producing organisms as they are is a challenge to God. God, for all intents and puporses probably made the laws and principles that guide the universe. This doesn't mean he had a direct hand in every little detail, in other words he didn't bother 'poofing' a flagellum into existence through a miracle. Rather natural laws that were set in place originally may have allowed life to 'self' assemble itself. It seems to me that a 'designer' that doesn't have to do the work himself, rather lets a series of basic laws design everything without his direct influence is much more intelligent than one that micromanages every aspect of life. This is why we don't see any 'meddling' at all, because it was never required to begin with because the natural laws put in place to begin with were more than sufficient (which we know are still operating today)
Of course, this is heavily putting God around 'evolution', clearly knowledge that humans have accumulated but it's so well and truly supported that for the creation story to be true, it makes God a distinct liar. As a result, the only 'God' that evolution seems to contradict is those that read a literal 6 day creation model, which time and time again has been found to be deficient in terms of scientific evidence. Of course, I fully understand that many also see that evolution and natural laws providing evidence that you don't need God is perfectly reasonable as well. I often wonder why it is that the religious require to concile their belief in God with evolutionary science, but not germ theory, weather forcasting or any number of other sciences that do not claim God was an essential part in the way they work.