Violence exists because we are social animals. We live and find our identity in groups. And groups conflict. They fight over the same resources: food, territory, other scarce goods. That is our nature and it leads to all that is best and worst about us: our altruism towards other members of our group, and our suspicion and aggression towards members of other groups. Religion plays a part in this only because it is the most powerful source of group identity the world has yet known.
