You are provoking a fallacy:
Argument from Ignorance http://en.wikipedia.org/wiki/Argument_from_ignorance
Why does it have to be a who?
If the world works naturally now, why could it not be created naturally too?
Long story short, this is where religion thrives, "There HAS to be an intelligent creator who made all this".
In reality, none of those religions can prove just what they spew it true. We don't know what made Time and Space, but it is NOT a free pass for you and your people to make up fairy tales
of a magical god who supposedly always existed even though that is not possible, because you know, the Time and Space thing we discussed.
This is also known as the God of Gaps argument http://en.wikipedia.org/wiki/God_of_the_gaps
(Not a good thing)
Which goes like:
"Guys, we just don't what happened here."
"Yeah, then it must be God, since there is an absence of an explanation."