Popes also sell a theory of everything, one that is called "religion". "Anyone who does not pray to the Lord prays to the devil" said pope Francis in one of his first speeches.
But the sentence is wrong on many counts. The most important one: the devil does not exist. Jews know that the devil does not exist. Science knows that the devil does not exist. The "devil" is a figure that appears in bad religious comics. How can somebody pray to something that does not exist?
Catholics must believe that the devil exists. It is part of their belief system. How can a world religion require people to believe falsehoods?