When religious people violently attack other people over religious beliefs, is it because of some kind of hatred cultivated over time that eventually devolves i

When religious people violently attack other people over religious beliefs, is it because of some kind of hatred cultivated over time that eventually devolves into something clinically diagnosable, or is it the other way around? Is it possible that a small subset of people with deep mental illness go into religion, politics, or any other self identity (possible as a form of finding social support), and through that the outgoing violence get focused towards a specific out group. Cause and effect. It not happenstance since what people choose to self identify with is not random, but the chain of events can just as easily be explain from both directions.