Humans do not naturally disagree with something and go to war over it. We are not as barbaric as we're made out to be. Human's naturaly love. It is only a very small percentage of people who actually crave chaos, war and destruction. It just so happens these people are the people in power.
Take away their power and they have no means of deceiving us into war. Nature/anarchy has a perfect self balancing equilibrium. No man made law can ever match the supreme law of cause and effect - karma.
You just said it.
It is only a very small percentage of people who actually crave chaos, war and destruction.These are the type of people who are motivated to power. Religion is a tool used for power.
Even if that didn't exist like the OP stated, these type of people would still figure out a way to gain power and control the majority of "lovable" people.
You are considering a perfect world. It doesn't exist dude and never will.