I think christians are eventually going to snap and kill everybody they can before they get taken out. If you're told your whole life that being fair and honest is important because God is coming back, and you go your whole life abstaining so you get into heaven, and then one day you realize you've been tricked, and there is no God, and he does not care, and he's not coming back...you are pretty much prepped to go off, psychologically.
Realizing that not only have you been tricked, but that there's others who have not been tricked who are doing "bad" things and not being punished for it, is not going to make you snap out of it and say time to move on, the values are ingrained in you and they're not coming out, so at that point you'll probably fly off the handle and start inquisitioning people for being "filthy" until you get inquisitioned yourself.
Religion serves two purposes:
1. Makes your subjects more passive toward you
2. Makes your subjects more violent to outsiders