Christian, your misunderstanding of the Big Bang theory stems from not understanding the timeframe. What happened "before" the Big Bang is not part of the theory and therefore irrelevant to the theory itself.

This is very similar to the religious misunderstanding of evolution, where creationists think that evolution claims life originated from nothing. It doesn't. Nor does the Big Bang claim the universe originated from nothing. The Big Bang theory makes no claim at all about what happened to cause it.

There are however OTHER theories (or maybe just speculations) that tackle the ultimate origin of the universe. I say "speculations" because one part of the Big Bang theory is that since the universe including time began at the Big Bang, anything happening "before" the big bang happened outside the observable universe and is therefore not bound by the normal rules of science.