[Cletus.D.Yokel]

:: priesthood of all believers, cardinal doctrinal principle of the churches of the 16th-century Reformation, both Lutheran and Reformed ::

Fail.
Grace alone.
Faith alone.
Scripture alone.

The Reformers did not cite TPOAB as a doctrinal free-for-all.
The Post-modern Western “churchiness” cult did this in order to justify destroying the God-given (Leviticus) Liturgical life of God’s people.
These heterodox, too, espouse Gnostic teachings such as “thus do not need a priestly mediator”.

[Pete from Shawnee Mission]

Cletus; I did not ask Brave search to look for the three "Solas. At this point I do not recall the search term, but I was looking at Nestorianism and Monophysite heresy in the context of the Spread of Islam and thought I could make a quick contribution to the discussion.

Beyond that I am not going to try involve the Q thread in the Rift between the Eastern and Western Church or the Protestant reformation.