You are implying that Mario is Catholic because he is nice. This makes little to no sense, seeing as it implies a correlation between niceness and religion. Nobody said nice people had to be catholic, or that bad people (as clearly represented in GTA games) had to be anything but. A better way to assume that Mario is Catholic is that he is Italian, and 97.2% of Italians are baptized catholics. This also doesn't mean that Mario is Catholic. I'm a baptized Catholic, but I'm also an Atheist. It isn't our choice to be baptized, that is done without our will. And just as Richard Dawkins states in "The GOD Delusion", "Speak of a 'child of Catholic parents' if you like; but if you hear anybody speak of a 'Catholic child', stop them and politely point out that children are too young to know where they stand on such issues, just as they are too young to know where they stand on economics or politics."