Interesting article. I have heard the attitude from some fundamentalists that Christianity became apostate immediately after the last apostle died and the church was wrong about virtually everything up until the time of the Puritans or the more radical reformers such as Zwingli. Up until then, almost no one was “saved.” I guess it would make one insular if one thought of the Eastern churches, Catholicism, and perhaps the more Catholic-like types of Protestantism as another religion. I don’t think understanding has always gone well both ways. Maybe we can have a little solidarity as we have common enemies.
I know a person who doesn’t believe anyone (or very very few) persons is saved besides himself. The doctrine this person follows is extremely contentous and divisive for Christianity.