>>839195
Everything a king says is not a law or an edict, but that only which a king says as king and as a legislator. So everything the Pope says is not canon law or of legal obligation; he must mean to define and to lay down the law for the sheep, and he must keep the due order and form.
We must not think that in everything and everywhere his judgment is infallible, but then only when he gives judgment on a matter of faith in questions necessary to the whole Church; for in particular cases which depend on human fact he can err, there is no doubt.
Theologians have said that he can err extra cathedram, outside the chair of Peter, that is, as a private individual, by writings and bad example. But he cannot err when he is in cathedra, that is, when he intends to make an instruction and decree for the guidance of the whole Church, when he means to confirm his brethren as supreme pastor, and to conduct them into the pastures of the faith. For then it is not so much man who determines, resolves, and defines as it is the Blessed Holy Spirit by man, which Spirit, according to the promise made by Our Lord to the Apostles, teaches all truth to the Church.
Rejection of Papal Infallibility is Rejection of the Sovereign qua Sovereignty.
>>839177
Mark 16:16-18
He that believeth and is baptized, shall be saved: but he that believeth not shall be condemned.
And these signs shall follow them that believe: In my name they shall cast out devils: they shall speak with new tongues.
They shall take up serpents; and if they shall drink any deadly thing, it shall not hurt them: they shall lay their hands upon the sick, and they shall recover.
Perhaps each one says to himself: "I, now, have believed, and therefore I will be saved." He says true, if his faith includes works. For true faith demands that one does not contradict in one's conduct what one affirms by his words. This is why Saint Paul says about some false believers: "They profess to know God, but they deny Him by their deeds." (Titus 1:16). And Saint John: "He who says he knows God, but does not keep his commandments, is a liar" (1 John 2:4).
Indeed, we are truly believers only if we fulfil in our works what we promise in our words. On the day of our baptism, we promised to renounce all the works and all the seductions of the ancient enemy. May each one of you consider himself with the eyes of the spirit: if after baptism, he keeps what he promised before baptism, that he be certain to be a true believer and let him rejoice. But if he fell by committing bad deeds or desiring the seductions of this world, he did not keep what he had promised.
Matthew 16:16-19
Simon Peter answered and said: Thou art Christ, the Son of the living God.
And Jesus answering, said to him: Blessed art thou, Simon Bar-Jona: because flesh and blood hath not revealed it to thee, but my Father who is in heaven.
And I say to thee: That thou art Peter; and upon this rock I will build my church, and the gates of hell shall not prevail against it.
And I will give to thee the keys of the kingdom of heaven. And whatsoever thou shalt bind upon earth, it shall be bound also in heaven: and whatsoever thou shalt loose upon earth, it shall be loosed also in heaven.
As St. Peter, by divine revelation, here made a solemn profession of his faith of the divinity of Christ; so in recompense of this faith and profession, our Lord here declares to him the dignity to which he is pleased to raise him - that he to whom he had already given the name of Peter should be a rock indeed, of invincible strength, for the support of the building of the church; in which building he should be, next to Christ himself, the foundation stone, in quality of chief pastor, ruler, and governor; and should have accordingly all fullness of ecclesiastical power, signified by the keys of the kingdom of heaven.
Also note, that Christ, by building his house, that is, his church, upon a rock, has thereby secured it against all storms and floods, like the wise builder of Matthew:
Matthew 7:24-25
Every one therefore that heareth these my words, and doth them, shall be likened to a wise man that built his house upon a rock,
And the rain fell, and the floods came, and the winds blew, and they beat upon that house, and it fell not, for it was founded on a rock.
And as the church is here likened to a house, or fortress, built on a rock; so the adverse powers are likened to a contrary house or fortress, the gates of which, that is, the whole strength, and all the efforts it can make, will never be able to prevail over the city or church of Christ. By this promise we are fully assured, that neither idolatry, heresy, nor any pernicious error whatsoever shall at any time prevail over the church of Christ.