So I guess you have to wonder why they're all so supportive of Sola Scriptura.
One also has to wonder why protestants are so keen on figuring out who the Whore of Babylon is, and whether it might be the Catholic Church, when, if the bible is 100% correct the Whore of Babylon will be just a whore who lives in Babylon.
Christ is not a "door," even though He refers to Himself as such.
It really doesn't take all that much discernment to deny the cannibalism that Rome foists off on its indiscriminate members. We "feed" on Christ because He provides our spiritual nourishment and everything else we need, for that matter. In this case, calories really don't count.
Regarding the "whore of Babylon," if it walks like a whore of Babylon and it talks like a whore of Babylon, it would be wise to clean up its act.