When I was a kid I didn't believe atheists really existed
As I grew older I began to doubt things myself. This doubt grew into full blown atheism. I now can't understand how anyone could believe what they read in the bible or any other so called holy book.
For a select few atheism comes naturally. In others it develops to a point where you can't return to the woo woo nonsense you read in the bible or hear from some minister or any other type of person who believes in fairy tales.
You go to a supposedly haunted house and no ghost appears. Poof there goes the supernatural. There are no ghosts, spirits, demons, angels etc. Just cold hard reality.
Some believers ask this question "how did we get here"? My answer is this. I don't know and neither do you. Life forms through natural processes the beginnings of which are unknown.
As an atheist lays dying his or her only fear is oblivion. No anticipation of paradise or fear of H***. Death isn't the great unknown to an atheist. Its the end.