What it Takes to be an Atheist

On my favorite Sci-Fi show, Startgate: SG-1, the team finds an alien machine that allows them to travel between different universes. One of the characters on the show says that according to scientific theory, at every instant, all possible futures happen in alternate parallel universes.

Dawkins, in the God Delusion, acknowledges that our current universe is so unlikely to exist, that one must adopt theories like this to explain the universe.

Here are the two competing theories:

The universe is finely tuned:

1) because God created it that way
or
2) because we just happen to inhabit one of the infinite number of universes

To objectively and rationally look at the theories, let's look at the evidence:

1) God revealed himself in history through his son Jesus Christ. The historical evidence we have today is more abundent that any other historical figure of that time.
or
2) Mathematical equations that 'prove' multiple universes.

So, the question is, which is more likely, given the evidence?