We don't know.<quoted text>
You said everything was there before TBB. What actually was there before the TBB? Use detail!
So what is wrong with saying "we don't know"?
One other thing. We are trying to find out, using a methodology (observation and logic) that has worked pretty damned well up until now.
You on the other hand seem to accept a pat answer i.e. Goddidit, but with absolutely no backing other than ancient goat-herders with visions claimed Godidit. They also claimed serpents talked, dove's blood cures leprosy, God told them to commit genocide, and that their supposed omniscient God could feel regret.
mmmm. Shouldn't be too hard to decide which way to bet.
Oh wait, I forgot.
The men with visions promised you would get to live forever if you believed their malarkey. That changes everything.