Atheists!! To what extent do you believe in... Big Bang theory..?

Until some one comes up with a better explanation for the expanding universe and inflation , I'll stick with it.

The "Big Bang Theory" is a fact. That's what "theory" means in science. All educated people, atheist and theist, recognize this fact. What caused the Big Bang is where religion separates from science, since science has no answer at all to this question.

Why did you ask this question again??

I saw and answered it the other day...! :/

I'm not sure, but this looks like a trick question. But concerning "The Big Bang Theory," I'm glad that Leonard and Penny finally got married. 

It's not a theory. It's a hypothesis. It's never been proven. Typical of theoretical physicists, there is now faction that is trying to rescind its occurrence.

Its not about believing, its about understanding and trusting in those who have done the science and hard work to confirm it. I accept that this is the best current explanation for the expansion of the universe. 

There's a great deal of physical evidence for the big bang, like the cosmological expansion constant and the existence of the cosmic background radiation.  So, yeah,  Hallelujah!  I believe!  I BELIEVE, I BELIEVE!

It's the most well-supported theory that explains the continually expanding nature of the universe. It's not something I can see as clearly as fossil and DNA evidence but the evidence we have for it is quite convincing.

It's an extrapolation back of star movements. It's good enough for now. Atheists accept "We don't know for certain" about origins of the universe, life, humans, after death.

It's better than a timeless invisible omnipotent omniscient entity did everything.

No effect at all on my life. I hold self-integrity as my most valuable possession, and that's better than a lot of people who sell theirs to cheat or lie for profits.

It's the best model we have right now, and it turning out to not be true would raise a lot of questions. Like where the CMB comes from, why the furthest away galaxies look so young, and how the universe's expansion works.

But at the end of the day, that's all that would be upset by that. The standard cosmological model. It isn't really something I'd need to hold onto as true if conflicting evidence was discovered. Really, no aspect of someone's world view should ever be THAT important.