Such an assumption denies the Christ, Son of the Living God, for it was the Christ who emphatically declared, taught and re-emphasised:
All four promises to Peter alone:
“You are Peter and on this rock I will build My Church.” (Mt 16:18)
“The gates of hell will not prevail against it.”(Mt 16:18)
I will give you the keys of the Kingdom of heaven." ( Mt 16:19)
“Whatever you bind on earth will be bound in heaven.” (Mt 16:19) [Later to the Twelve].
“Strengthen your brethren.” (Lk 22:32)
“Feed My sheep.”(Jn 21:17).
How could these commands be fulfilled if Peter or his successors could TEACH error? Do they think that the Christ lied?
And the authority of the Pope is that of Christ. Of him Christ said, “He that heareth you, heareth Me; and he that despiseth you, despiseth Me.” [Lk10:16]. Again, Christ said, “If a man will not hear the Church, let him be as the heathen.” [Matt. 18:17]. Our Lord could never have commanded men to obey two conflicting authorities.
No Magisterial dogma or doctrine has ever been revoked, or can be shown to be wrong, notwithstanding some bad and immoral Popes.
Further Christ and Christ’s chosen, from the Sacred Scriptures His Church gave us, have warned against just such Protestant errors, as the Sacred Scriptures confirm Christ’s expressed conferring of authenticity:
I will not leave you orphans; I will come to you." (John 14:15-18) “The Advocate, the Holy Spirit that the Father will send in my name, he will teach you everything and remind you of all that I told you.” (John 14:26) “But when he comes, the Spirit of truth, he will guide you to all truth. He will not speak on his own, but he will speak what he hears, and will declare to you the things that are coming. He will glorify me, because he will take from what is mine and declare it to you. Everything that the Father has is mine; for this reason I told you that he will take from what is mine and declare it to you.” (John 16:13-15)
Jesus warned dissenters: “if he refuses to hear even the Church let him be like the heathen and a publican.” (Mt 18:17).
St. Paul has counseled you as to whom to avoid: “Preach the word. Be urgent in season, out of season; reprove, entreat, rebuke with all patience and teaching. For there will come a time when far from being content with sound teaching, people are avid for the latest novelty and collect themselves a whole series of teachers according to their own tastes.” (2 Tim 4:3).
The Church is "the pillar and bulwark of the truth” (1 Tim 3:16).
St. Paul says also, “through the Church the manifold wisdom of God might now be made known to the principalities and powers in the heavenly places (Eph 3:10).” The Church teaches even the angels! This is with the authority of Christ!
St John counsels: “We belong to God, and anyone who knows God listens to us, while anyone who does not belong to God refuses to hear us. This is how we know the spirit of truth and the spirit of deceit.” (1 Jn 4:6 ).
In Colossians 2: 4-23, St Paul calls on his flock to follow Christ “as you were taught” and warns against merely “human precepts and teachings.”
1 Cor 1:10: I urge you brothers, in the name of Our Lord Jesus Christ, that all of you agree in what you say, and that there be no divisions among you, but that you be united in the same mind and in the same purpose.