Haha you're an idiot Yoyo. Luckily I know you're trying to stir little Hisashi.
As for Hisashi's theory, it's based on comparing Catholicism to another specific form of Christianity.
BOTH are forms of Christianity.
Protestants, Catholics and any of the other numerous religions who believe in the word of the bible (specifically the new testament, or the WHOLE bible, not just those parts shared with Judaism and Islam) and that Jesus was the messiah, are Christians.