I hadn't tuned my guitar to the piano in several months -- not that I'd played it a lot, either. Anyway, I had to drop every string at least a whole step to match the piano's pitch. There's a lesson here. If you keep tuning the instrument to itself, it'll sound right, but get increasingly off-pitch. In the same way, if you keep tuning your beliefs or your sense of right and wrong to yourself and whatever is the consensus among people around you, you will get farther and farther off. We have to keep coming back to the Bible and the Creeds and the living tradition of the Church.
And this need to check yourself against the authoritative sources holds for clergy as well as laity, for the old as well as the young, for the teacher as well as the student. All of us, without an external source to check ourselves against, will tend to accommodate ourselves to whatever is current, is fashionable, or just prevents an argument. It sounds right to us. But it's not, it's off. "To the teaching and to the testimony!" as Isaiah said. Even though what is emerging seems righteous -- certainly it is approved by all the right people -- nevertheless, "Surely for this word they speak there is no dawn."