But if you start calling him "unchristian" or "heretic" you are no different from the most hidebound medieval Pope.
Hmmm. I think there is more to it than you mentioned...
And there is the place of of leadership to settle disputes:
It belongs to synods and councils, ministerially to determine controversies of faith, and cases of conscience; to set down rules and directions for the better ordering of the public worship of God, and government of his Church; to receive complaints in cases of maladministration, and authoritatively to determine the same... - Westminster Confession, Cp. VI:
But if you start calling him "unchristian" or "heretic" you are no different from the most hidebound medieval Pope.
Which depends upon how Catholics interpret their own church, while they attack Bible Christians for interpreting Scripture, which Caths can also do in variance. Ever read some of the notes in the NAB ?