What kind of moron Christian says Catholics aren't Christian?

Christianity didn't begin in the 1500's. Whats even more ironic is how all the Romans that were persecuted for being christian, are used as an argument against atheism and how we're trying to persecute them, but at the same time calling them non Christians. They were Catholic. Catholicism is the original christian church, and they do worship Jesus as their lord and savior. They also honor Mary as being "Worthy" enough to bear Jesus as a virgin. Or so I'm guessing, but that's besides the point.