One argument I commonly come across when talking to my mother about the big bang is that it's an unstable theory since scientists have no idea what caused the big bang in the first place.
I don't know if this is an argument that is prevalent throughout the Christian community, but what I do know is that it is possibly the dumbest one I have heard in a while, even above the ridiculous argument that we can't trust scientists when they say evolution is true or that the world is 14 billion years old because they're all liars who only want to deface Christians around the world!" The argument that we don't know how the big bang started and so therefore renders it invalid is mind-numbing to me. How can anyone even make such a claim and still keep a straight face!? First of all, I could just as easily make the same argument against God. What created him? Is there a God of Gods who just creates miniature versions of himself just because? If so, what created this Mega God? And what created the Mega Mega God, if there is such a thing? I could go on and on, but I won't because that would get us no where.
Secondly, we actually have more evidence for where the big bang came from than you have for where this God of yours came from. Quite a few scientists think that the big bang formed when a universe that came prior to us collapsed in on itself, creating this small, compact, immensely dense ball of matter. This ball of matter then burst outward, creating our current universe. How was the previous universe that collapsed created? We don't know. We're not even sure if this is a true theory, but it sure makes a hell of a lot of sense. The point is, we at least have a clue, which is more than anyone could say about the people who make outrageous arguments about our lack of knowledge.