I'm gonna go with Al's original line of thought: what a stupid question.
Stupid, Gustaf? Probably nothing in history has cause more wars and death than religion........now that's stupid.
How does that makes the question less stupid? What has Christianity ever done for humanity? Knives have probably caused more deaths than most inventions but asking what knives have ever done for humanity would be still mind-blowingly stupid.
Most of those wars and deaths were hardly about religion anyway. They were often power grabs and in many other cases an effect of the evolutionary instinct of human beings to identify others as enemies and kill them. These others can be defined in different terms but the terms themselves are not really to blame.
