I've always wondered this and I'm young so I have no idea about any of this. I'm Jewish with no strong beliefs, I just like the values of my religion but the beliefs seem a little off to me. I'm undecided on a deity or afterlife because I really don't have the time or energy to think about that s***. I've always wondered about the big bang, though: how did the matter that condensed get "there," wherever there is? Or, "when matter came into existence," as you said; how did it come into existence? What are the theories behind that? It's always just seemed so spectacularly beyond me, creating something out of nothing.
These are genuine questions and you're a smart mofo which is why I ask. These aren't meant to start fights or anything lol.