As for the article of Hus that “it is not necessary for salvation to believe the Roman Church superior to all others” I do not care whether this comes from Wyclif or from Hus. I know that innumerable Greeks have been saved though they never heard this article. It is not in the power of the Roman pontiff or of the Inquisition to construct new articles of faith. No believing Christian can be coerced beyond holy writ.

via From Luther to Leithart » Mark Horne.

Thus Luther rejected Eck’s proposition and thus he defended the Gospel. Believers are right with God because they are believer regardless of what they believe about the Pope even if it were true. Luther had a jus humanum view of the papacy (as did many other medieval Christians; the idea that everyone accepted the supremacy of the Pope in the way modern Catholics demand it is an example of the victors–over a sect–writing the history). So he himself, at the time he argued with Eck, actually accepted the office of the Papacy. He still didn’t think it could be necessary for salvation.

But he also never bothered to address the question as to who was at fault in “The Great Schism.” Since he was a Western Christian, Luther probably took it for granted that the Eastern Christians should have stayed in union with Rome. But whether or not that is the case, in his response to Eck, he doesn’t think it was worth mentioning. It doesn’t matter. Believers are justified. Period. Full stop. They have zero obligation to engage in a historical study to make sure there is no “sin of schism” in their ecclesiastical “lineage.”

And likewise today, whether or not the Ecclesiastical splits of the Protestant Reformation were justified is a logically unrelated question to whether or not Protestant Churches are real churches or whether Protestant Christians are real Christians.

Protestants who pretend that all stands are falls on whether or not the Ecclesiastical divisions were justified are sliding away from the doctrine of justification by faith and sliding into a doctrine of ecclesiastical successionism.