"Even though the bishop of Rome had the primacy and superiority by
divine right, nevertheless obedience would not be due those pontiffs
who defend godless services, idolatry, and doctrine conflicting with
the Gospel. Nay; such pontiffs and such a government ought to be held
accursed, as Paul clearly teaches, Gal. 1:8: Though an angel from
heaven preach any other gospel unto you than that which we have
preached unto you, let him be accursed. And in Acts 5:29: We ought to
obey God rather than men. Likewise the canons also clearly teach that
a heretical Pope is not to be obeyed."
-- The Smalcald Theologians (Lutherans), 1537.