Darwin didn't set out to disprove God. He set out to explain the things he was observing in the world around him. Neither the theory of evolution nor science in general have anything to say on the existence of a Magical Fairy in the Sky. It's irrelevant.

If atheists find evolution "comforting" it is only because it allows us to explain one of the great questions the universe--how do we explain the diversity of life?--without resorting to an unscientific cop-out of "Goddiddit". Evolution, along with all other powerful scientific theories, puts another coffin nail in the notion that supernatural--i.e. useless--explanations are necessary to fill in the gaps.