Overview
While atheism isn't technically a religion, atheists still has their own beliefs on the creation on the universe. Therefore I have decided to include it. Atheism is the lack belief in a god or supreme being. There are many different types, but all atheists don't believe in a higher power. Atheism is large and growing, but it is very hard to know how many atheists there are. This is because people define atheism differently or are scared to come out to family and friends. The number of atheists ranges from 500 million to 1 billion. Atheists are found just about everywhere, but some highly concentrated countries are China, Russia, and Sweden.
Cosmogony
Most atheists believe in the big bang. It's pretty confusing and largely scientific, so this is just a small and brief description. The universe started as a very dense and chaotic singularity with no atoms or anything like that. Then about 13.7 billion years ago, it started rapidly expanding. Material in the singularity formed into atoms and later into elements. This continued on and on until now with a large and expanding universe. There is much more detail of the big bang theory, but this is just a simple explanation of it.
Some Helpful links
https://www.space.com/25126-big-bang-theory.html
https://simple.wikipedia.org/wiki/Big_Bang
https://en.wikipedia.org/wiki/Big_Bang
https://www.atheists.org/activism/resources/about-atheism/
https://simple.wikipedia.org/wiki/Big_Bang
https://en.wikipedia.org/wiki/Big_Bang
https://www.atheists.org/activism/resources/about-atheism/