From Walter Jon Williams:
Angel Station: Audience Participation: Still working. And so, clearly, the only way to keep us both amused is to make you talk. Here's a quote from Steven Weinberg.
With or without [religion], you would have good people doing good things and evil people doing evil things. But for good people to do evil things, that takes religion.
I agree with Weinberg and Williams. The problem of evil--why does God make a world in which bad things happen to good people?--is a hard one. But the problem of supernatural evil--why does God make a world in which good people do bad things in the name of God?--is a much harder one.