Wars didn't happen because of religion. They happned because of humans. The religious wars of the past were meant to increase one's power. The crusades, the best exemple, they were created to get land and gold, because that was power back then.
Spreading some religion, that was just an excuse.
How do you explain, in the religion wars in europe, a guy supporting a religion in his country, and supporting the ohter in another country? Does that really seem because of that religion, or is because that was what was going to keep him in possesion of his power?
As this is true, the opposite is also true. Religion doesn't bring peace. Those ideals about love and respect, that's what brings peace. You don't need to be religious to achieve those ideals, and being religious doesn't mean you respect and follow them.
What can we conclude? That by changing our behavior, we can make peace. Blaiming religion to be responsable of our problems won't solve anything. We, humans, created those problems. And of course, putting our hopes on it won't solve anything either.