Darwin was a life-long Christian. He began his college career as a divinity student, with the goal of becoming a pastor. He never saw his theory as questioning the existance of God and he never recanted his theory on the origin of species.
I support evolution as much as the next man, but Darwin, after the death of his child, became either an atheist or the next-best thing. Darwin's death-bed conversion is, however, apocryphal -- claimed much later by a single supposed witness, and ultimately irrelevent. Because he never recanted his work, nor could he have, because the evidence is overwhelming.
As for evolution and God being compatible, many scientists (including myself) consider themselves to be people of faith and don't have a problem with evolution.