If the universe has a beginning does that prove God exists?

Question

It is curious to note that a eminent Physicist like Stephen Hawking thinks the universe has a beginning. This has some rather startling Religious implications

Answer 1

I think at most, it would entail that something independent of space and time exists. Physicists might say that physics or the laws of physics explain the beginning of the universe. Stephen Hawking, however, also suggests it to be possible that nothing caused the Big Bang, since the Big Bang was the beginning of the space-time universe and thus there is no time "prior" to the Big Bang. I think many would contest here by suggesting that even if there is no time "prior" to the Big Bang, there still must be something (that'd be atemporal or "outside" of time) to cause it to occur. For theists, there is no better candidate than God for what/who the cause of the Big Bang is.

So this debate hinges on the following two questions:

1. Does the beginning of the universe (or the Big Bang) have a cause?
2. If so, what is that cause?

To prove that God exists, the first step to prove that God exists would be to answer (1) affirmatively and then the second would be to prove that God is the only possible candidate to be the cause of the universe.