I'm a bit more optimistic than that, both about religion and about humanity. But I agree we've got a long way to go toward learning to live with one another and the rest of life on the planet in any kind of equilibrium.
To me, strong identification with any small group (by which I mean "smaller than the sum of humanity," really) is where we get the problems. Anyone "in" the group is ok, and their flaws are overlooked (or they get thrown out of the group), and anyone "out" of the group is somehow less than human, and fair game for anything the group wants to do. This is by no means confined to religion. Political parties, economic ideologies, geography, and accidents of birth (i.e. "class") all have the same effect.
I have a working theory that if we tried to make the world a bit more "fair," with more equitable distribution of resources and opportunities (at least at birth and for children), much of the motivation for this kind of nastiness would go away, but oddly enough, I'm having trouble finding a way to test this theory....
