This is my theory derived from theory of Stephen Hawking in which he told and proved that there was no time before big bang, time started just the moment after big bang.
So my theory if we consider his theory is if there was no time before big bang then there was no time for a God or creator to create our universe. Which means the big bang took place on its own not by any creator.
There may be some other reasons for the taking palace of big bang .
If you have any more idea to make this theory better or any contradictions to this theory then please tell me by discussing.
The big bang itself isn't fully approved yet as it doesn't follow the first law of thermodynamics the law of total entropy however there was this another theory of cyclic universe which is more prominent
I would like to say something...see god or creator of the world is totally mythological concept as it depends from person to person to believe in god or not as no one knows if really exists but everyone knows that science exists in each and everything of the world...this big bang theory isn't a mythological topic instead it is a phenomenon that took place millions of years ago due some changes in the universe...there was a scientist named "Georges Lemaitre" who first noted in 1927 that an expanding universe could be traced back in time to an orginating single point calling his theory that of the 'Primeval Atom'..from this theory I I would to like to draw the my theory out of it that originating point of the universe must be the place where big bang took place due to some reactions...and not due to creator of world...I hope this helps you.