If matter went into a black hole and somehow came out through a white hole, wouldn't it appear to go poof into existence from nothing? There are also theories that a Big Bang could occur within a black hole. Poof into existence from nothingness. But what about wormholes? What if a wormhole just opened up and something came though, from elsewhere in the universe, or from elsewhere in the multiverse? Wouldn't it just appear to go poof into existence from nothing? Or what if some kind of cosmic, godlike being emerged through one such cosmic doorway from another universe, and somehow caused a Big Bang to occur which led to the formation of the cosmos? It would appear to go poof into existence from nothingness.
Let me expand a bit on this idea of "poofing into existence from nothingness" because it actually is something science has observed happening on the subatomic level all the time. Electrons poof into and out of existence, appear in two places at the same time or nowhere at any time. It happens on the subatomic level all the time and we never are aware of it. There are three places where we know our fundamental laws of physics break down. 1) before the creation of the universe, 2) at the subatomic level and 3) inside a black hole.
I have often said, most of us believe in Creationism. We can debate the source of the creation but unless you believe the universe was created by something you have to believe in supernatural fantasy. Both physics and spiritualism concur, we are the product of creation.