I've heard many religious people mock the big bang theory because they question that how did nothing turn into something. But then in that same thought, where did God come from?
I prescribe to the modern Kalam Cosmological argument. In essense, whatever began to exist has a cause and since the universe began to exist it has a cause which Christians belief is God. God stands outside the concepts of time and space which both had beginnings and those beginnings would necesitate a uncaused cause, an infinite all powerful creator. This is a crude, brief explanation, but this isn't my area of expertise so expounding (on my part) would be comical.
Certainly this position has its objectors, but what positions in theology and philosophy don't LOL?
Modern science claims the big bang was caused by an explosion of highly dense matter that is ever expanding the universe; although, (at this point) science neither knows where the dense matter came from or what triggered the explosion. Physicists are trying to eliminate the need for the original catalyst/cause/singularity and believe that all that is needed is more time in order to discover why the big bang was the big bang. In my humble opinion, more power to them and I hope they do, but I believe that search will inevitably lead them closer and closer to the creator I serve.