What things lead to the formation of the Cosmos?

The things that lead to the formation of the cosmos are debatable. Some Christians say it was all created by God and that is that. But science has more to say about the subject by the way of theories. The Big Bang denotes that there was an explosion of sorts and boom, the cosmos and all it entails was in existence.

There really is not one set answer that is not a theory as of yet. In time, there most likely will be though. Until that time, it remains a mystery.