While still quite hypothetical, it might be the case that there is no 'nothing'. Not in the sense that we usually mean at least. Vacuum appears to have energy, and energy is certainly not nothing. We are still looking for a large amount of antimatter or an explanation for the lack thereof to explain the big bang, but matter and antimatter can come into existence. See it like this: if you are digging a hole on the beach, you are not only digging a hole, but a mound of sand as well, while first there was neither. That there are still some exciting questions in physics does not mean there's no answer for them. 'We don't know, therefore god' is not an answer that I am content with.
For a long time there were similar questions like "How can it be that positive and negatively charged materials attract eachother? That is action over distance! We don't know how it works!" But we now know that the electromagnetic force works by exchanging photons. Just because something seems impossible without magic, doesn't mean there's actually magic.
Edit: Ah, you were too fast for me Moriouce! Though Stephen Hawking does deny belief in God, as did Einstein. However, you can't disprove something that is constructed as such that it cannot be disproven. You cannot disprove god, no, but neither can you disprove an invisible, immeasureable omnipresent octopus.
Stephen Hawking on the matter: