Then what do you believe?
God has sustained and ordained the unfolding of the universe from the Big bang through stellar evolution, planetary evolution and biological evolution up until the present day. With God nothing is "an accident".
However, even an atheistic view of evolution is not just "an accident". The processes of natural selection are not random. For the origin of the universe, from an atheist's perspective, you might be able to say "accident" if you take certain views of it. Even so the processes after the big bang are in many ways orderly.
So you don't believe God had a hand in it?
I didn't say that. However science does not currently (and may never) know what was before the Big Bang. I'm not going to play "god of the gaps" and say because we don't know currently what caused the Big bang that God supernaturally caused it. Maybe He did. But certainly God is involved in creating and preserving the created order, up until the present day, so God was and is involved in creation, period.
And you can't think of how an explosion can happen without any gases?
It happened before there was matter- its what created matter and separated the forces of the universe.
This isn't like a gasoline explosion on earth. You know what protons neutrons and electrons are right?
At least Jukia explained nuclear fusion, whereas you mentioned it and nothing more. You assume too much.
You could have also taken two seconds and looked it up for yourself online too. You doth protest too much.
Then where did it come from? Do they even have a theory?
Where did what come from? the singularity? Some people think the universe oscillates back and forth and there may have been lots of collapses followed by Big Bangs rather than one. Or that there are multiple universes and we just happen to be in the one that supports life. So far as we know these are not currently scientifically testable so they are not much more than speculation.