A messenger delivers the message given by the sender of the message, and is not allowed, not authorized, to say anything but the message entrusted to him.
The doctrines of the Church are (among) the message(s) given to the Church to “require” of the people of the Kingdom established by Heaven, which is not established by this world.
The People of God, this Nation of Priests and Kings, this Strange People in the World but not of the World, does not ask, “Is this doctrine true?”, but this people asks, “Who is telling me this doctrine, is this the messenger sent from the Lord?”
Those outside the Kingdom are asking, “Is this or that true, is it truth?”
We ask, “Who are you?” of the messenger, “What is your vocation, and who sent you?”
Apostolic Authority, SENT AUTHORIZATION, by the King to us, his obedient subjects and siblings.
John Martin