If you want to see an atheist’s head explode, point out that the multiverse theory implies an infinity of universes with god(s), and an infinity without ... and ask, which one do you think we live in, and why?
Ha! That’s a wonderful, truly sci-fi concept.
Maybe there could be some Universes made by God, and some rubbish ones that just turned up by themselves.
Atheists don’t really care whether or not a God exists. They just don’t want One that takes a personal interest in them.