One theme which often comes up in the debate over evolution is that the anti-evolution side insists that evolution is anti-religion, while the pro-evolution side insists that evolution and religion have nothing to do with one another, so religious people should leave evolution alone. Strategically, there may be some merit in this argument. Certainly it is a fact that most of those who believe in evolution are also religious, so it's not as if believing in evolution requires you to reject religion.
However, I think there is a problem with claiming this total disconnect between the issues of religion and evolution. The main reason I am an atheist is because, when I look around at the universe, it doesn't particularly look like the sort of thing which has been designed by an intelligence for some purpose. Now, of course this is not a conclusive argument; intelligences are capable of having all sorts of strange purposes, and an intelligence capable of creating a universe would presumably be capable of having purposes far beyond my understanding. But, while it's always necessary to remind ourselves that we could be wrong, this shouldn't preclude us from accepting what our best evidence seems to be telling us, and in this case what that evidence seems to be telling us is that there's no God out there.
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).
The obvious response to this is to push the faith line, and say that belief in God has nothing to do with the evidence. I suppose there are some who would take that line, but I fear there are too many who retreat to this position when the going gets tough, while normally insisting that their beliefs about God are as reasonable as can be.