Actually, religion is rather incidental to these tragedies. It merely divides people into alien ethnic groups who mistrust each other. Then they grow paranoid over political power, economic inequality and other social antagonisms - and fear that the other side is arming against them. In Sri Lanka, for example, the minority Hindu Tamils are bitter because the majority Buddhist Sinhalese impose their language and religious holidays on the whole society. The current Mideast nightmare is another sad example of this tribalism.
Nobody knows a cure.