Do you think Big Bang theory is true?

Well, I don't believe in any type of higher being, but I'm not entirely sure how the earth began. I fairly positive that some omniscient, etherial being snapped his/her fingers and it automatically was. That just seems a bit bogus to me.

I like to believe the description of the big bang is what happens when God says "Let there be light"

It seems to be the most plausible theory out there at the moment, and the one the overwhelming majority of scientists subscribe to.

Did you know it was formulated by a Catholic priest?

Well, it's more believable than the Genesis myth. No-one will ever know for sure; this is why it's a theory, not a fact.
My personal opinion is that we've all been here before, evolved, hit our peak (whilst at the same time destroying the Earth), the sun has died, created a super-massive black hole - no-one knows where light and matter go when they go into a black hole, but i think it's all spat out the other side, in yet another 'big bang' and the cycle begins again. We're now heading towards the same thing again - the sun is dying, the Earth is slowing down, the poles are about to shift & none of this bodes well for humanity, but from a universal perspective, it's the only solution - rip it up and start again - from scratch. This could all be bollocks, of course, as i do like a smoke, but still, it's more realistic than Gabriel blowing his trumpet and the dead rising and all that apocalyptic clap-trap.

I think we've started to move beyond it.