This is one of the oldest, hoariest questions in the history of the Christian religion. If you ask any priest or minister, they will tell you that God always was, is and always shall be. Logically, one can argue that the world always was, is and always shall be. It is a no-brainer. If you are religiously inclined you will believe the teachings since you have been taught this from an early age. On the other hand if you are logically, or sceptically minded then you will believe the latter.
I have been out and bought a bible (something I have not read since school) I have just read Genesis , something I find interesting, but hard to believe.
I don't have any religious beliefs but obviously we must have come from somewhere and Chaos seems to me to be the only theory as to why there is a Universe.
And I also believe that we would all be ignorant to think that we were the only living beings in the universe. I'm sure that there are other beings inhabiting other planets which orbit other Suns.