For about a thousand years the only form of Christianity was Roman Catholicism The article on Christianity mentions the ProtestantCatholic schism in the lede However it does NOT state that some in each camp did not recognize the other as Christianand in fact some of that still holds sway today eg the antiCatholic Jack Chick tracts So we have the idea of historically something has been but does not state that those adherents do not usually recognize the other side as being part of them The upshot Argument from Antiquity is a fallacy no matter how you try to word it Same with Argument from Numbers  We could also look at the page on atheism Nowhere in that lede does it talk about communism as many people still equate atheism with communism or wickedness as even some dictionaries include that in the definition of atheism So what most might usually recognize as traditional isnt necessarily what it actually is now is it