Are the brothers religious?

I know this is a very random question and people here don’t really like when you ask random questions but I’m really curious because didn’t Lyle used to wear a cross necklace, and didn’t Erik have a bible group or something in prison (I think I read that somewhere I’m not 100% sure.) I also remember seeing something one of his relatives said about Erik asking for bibles and stuff so they must be.

I guess my question is more why are they religious if they even are? Not to get philosophical and I hope I don’t get hated for this but I just can’t comprehend how after everything they’ve endured they could possibly believe? This is coming from an uneducated atheist who doesn’t really understand the concept of religion so I really want to hear people’s opinions since I’ve been wondering this, prove me wrong people please 😓😓

Is this common for survivors of abuse? Because I would have assumed the opposite.