Why do the atheists get all their beliefs from the catholic cult?
The big bang theory, started in the 1920's by Georges Lemaitre, a priest from Belgium.
Evolutionary "evidence" called "piltdown man" later proven a hoax, given to the world by Pierre Teilhard de Chardin, a Jesuit.
Your "one" atheist belief doesn't explain where everything came from. You go to the catholic cult to get those explanations.