theists say God could have caused the universe. atheists say the universe could have caused itself. but the problem is we have reasons to think otherwise.
1. lower energy states come from higher energy states. something had to cause the first maximum energy state of the universe. as far as we know it from our reality, an energy state greater than the universe must have caused it to occur, because we have no reason to think the universe could have caused itself given it had a maximum energy state as a beginning.
2. existence should have an infinite beginning given it looks like there's an infinite end. i acknowledge there could be a finite end, but from what we can tell existence will be forever more even if it's emptiness. an infinite ending of our universe cannot have a finite beginning that we see. something else must be the infinite beginning. if i'm wrong, how can a finite beginning cause an infinite end? how does that series play out out of nowhere?
i acknowledge that there could be evidence that contradict these principles... the problem is that we see no such evidence in the universe, all we have is speculation that these presumed principles are faulty.