ST. VINCENT OF LERINS (CA. 400-CA. 450)
CONFESSOR OF THE CHURCH
“What then should a Catholic do if some part of the Church were to separate itself from communion with the universal Faith? What other choice can he make but to prefer to the gangrenous and corrupted member the whole of the body that is sound. And if some new contagion
were to try to poison no longer a small part of the Church, but all of the Church at the same time, then he will take the greatest care to attach himself to antiquity which, obviously, can no longer be seduced by any lying novelty.” (Commonitorium)
“he will take the greatest care to attach himself to antiquity which, obviously, can no longer be seduced by any lying novelty.”
Antiquity is what has always been taught. The infallible doctrines that NEVER can be changed.
There does not exist one original doctrine among Protestants that has not been changed to something else by other Protestants.