I also should say, publicly and for the record, that S. T. Joshi, America's foremost Lovecraft scholar, deserves a medal or a MacArthur grant or an endowed chair at Harvard or something. I suspect his politics are at sharp variance with mine, and I know his reasonably militant atheism would rub many members of this group the wrong way . . . but he has brilliantly rehabilitated Lovecraft in the eyes of the scholarly community. And he has thought deeply and well about the philosophical implications of weird fiction generally, and of Lovecraft's "cosmic terror" more specifically.
The "cosmic" perspective--the idea of human insignificance--is a philosophically-legitimate grounding for the atheist's world-view. It is far more convincing, at least to me, than Selfish Gene-style evolutionary reductionism. Evolution doesn't necessarily exclude religion, though it tends strongly to favor Deism; but man's existential insignificance, as expressed powerfully by Lovecraft, generally does. It's hard to give much credence to the notion that a loving God has a plan for every field mouse and every cold virus. . . So I can see how Joshi's studies of Lovecraft might have led him toward atheism (or, conversely, why he might have been attracted to Lovecraft in the first place). I think this tends to sit uneasily with Joshi's Left-of-center political beliefs (at least, insofar as I can ascertain them), but--hey--no one ever said scholars need to be consistent.
(Joshi edited the Machen book I mentioned in my previous post; and I thought I'd publicly acknowledge my admiration for him here.)