LOL. Shakespeare would have been a genius, even had he been an atheist. That he was a genius is in spite of, rather than because of, his (supposed) Catholicism.
Atheist can be a genius, — an evil one. The whole point about Shakespeare is that his personality as it comes through his work is profoundly Catholic Christian, even though a case can be made that the English mentality remained Catholic for centuries after forced conversion to Anglicanism.
Understand that religion makes the man. Atheism, for example, makes the man also, — into an animal, usually.