I'm atheist, but I still wonder where everything came from. If you really think deeply about it, where the -blam!- did everything come from?
A computer simulation? Yeah, then where did the beings that made the simulation come from?
From a God? Then where did God come from?
Everyone came from an infinitely small point in space? Cool, but how was all that made in the first place?
The "Universe is Infinite" theory? ....But did it all come from? How could everything just be there. It doesn't make since with current science. (Entropy, anyone?) Obviously, our current understanding of the Laws of Physics are wrong because they break down the closer you get to a Black Hole's even horizon.
In the end, we'll probably never know for sure how the universe began and where it all came from. Everything will forever be just a theory. And that's a little scary, if you think about it. Science might eventually be able to explain everything that's happening in the universe around you, but it will never be able to explain with 100% certainty where everything came from.