Any religion that teaches, even to their children: All the world is evil. World destruction is 'needed' for happiness. They don't need to kill anyone, but they have a "hit-man" (Jehovah) to take care of that. They will see the birds eating the flesh of millions/billions. They will be spending likely years, burying everyone's bones, but then they will find happiness. ???
This is a setup for some very disturbed people. Compound that with some living with critical racial issues now. Compound that with "gay" inclinations, when taught they are "evil" for that. Taught that if they aren't happy with their life and act out otherwise, then the most loving, good people, including their mom, will cut them off cold.
How the brain works through all that is very complicated. Children's brain cells fed that crap can be very critical.
Most can work through that positively, but ones need support, and need to start reading and living positive things. Identifying falsehood, learn to sort through negative thoughts. Some won't be able.
p.s. Be assured, this is not an excuse to kill innocents. I believe in the death penalty in such cases. Some then kill themselves in their misery and I wish they would do that themselves before any others.