I believe the universe was made by God, who doesn’t need to be explained. The only other option is that it came out of nothing or that our universe is one of a number of many millions of universes. This is the multiverse theory. Firstly, regarding the idea of the universe coming from nothing, we know that you can’t have something from nothing and it has almost been proven that the universe had a beginning when time and space began. So the universe began outside of time – it had a supernatural beginning. Regarding the multiverse idea, there is literally no evidence for this because we have no way of knowing about other universes, at least not yet. And if there were other universes, it simply takes the problem back a step. How did universes begin in the first place?