It comes out of the blue sometimes. I can be having a perfectly nice day and suddenly I start thinking about suicide---how to do it, when to do it---and visualize myself actually doing it. Then I think about what my death would do to my family and what would happen to me afterwards (I'm afraid of going to Hell because it's the one sin a person can never atone for). After I've visualized this whole scenario, the thought goes away and I resume my appointed rounds.

I don't know why this happens, but I've gotten so used to it that it almost doesn't bother me anymore.