Pope Pius XI: Mortalium Animos
"...And in what manner, We ask, can men who follow contrary opinions, belong to one and the same Federation of the faithful? For example, those who affirm, and those who deny that sacred Tradition is a true fount of divine Revelation; those who hold that an ecclesiastical hierarchy, made up of bishops, priests and ministers, has been divinely constituted, and those who assert that it has been brought in little by little in accordance with the conditions of the time...
...For the teaching authority of the Church, which in the divine wisdom was constituted on earth in order that revealed doctrines might remain intact for ever, and that they might be brought with ease and security to the knowledge of men, and which is daily exercised through the Roman Pontiff and the Bishops who are in communion with him, has also the office of defining, when it sees fit, any truth with solemn rites and decrees, whenever this is necessary either to oppose the errors or the attacks of heretics, or more clearly and in greater detail to stamp the minds of the faithful with the articles of sacred doctrine which have been explained. But in the use of this extraordinary teaching authority no newly invented matter is brought in, nor is anything new added to the number of those truths which are at least implicitly contained in the deposit of Revelation, divinely handed down to the Church: only those which are made clear which perhaps may still seem obscure to some, or that which some have previously called into question is declared to be of faith...
...During the lapse of centuries, the mystical Spouse of Christ has never been contaminated, nor can she ever in the future be contaminated, as Cyprian bears witness: "The Bride of Christ cannot be made false to her Spouse: she is incorrupt and modest. She knows but one dwelling, she guards the sanctity of the nuptial chamber chastely and modestly."[20] The same holy Martyr with good reason marveled exceedingly that anyone could believe that "this unity in the Church which arises from a divine foundation, and which is knit together by heavenly sacraments, could be rent and torn asunder by the force of contrary wills."[21] For since the mystical body of Christ, in the same manner as His physical body, is one,[22] compacted and fitly joined together,[23] it were foolish and out of place to say that the mystical body is made up of members which are disunited and scattered abroad: whosoever therefore is not united with the body is no member of it, neither is he in communion with Christ its head.[24]...
...11. Furthermore, in this one Church of Christ no man can be or remain who does not accept, recognize and obey the authority and supremacy of Peter and his legitimate successors...
St. Thomas Aquinas:
"It is also shown that to be subject to the Roman Pontiff is necessary for salvation. For Cyril says in his Thesaurus: "Therefore, brethren, if we imitate Christ so as to hear his voice remaining in the Church of Peter and so as not be puffed up by the wind of pride, lest perhaps because of our quarrelling the wily serpent drive us from paradise as once he did Eve." And Maximus in the letter addressed to the Orientals [Greeks] says: "The Church united and established upon the rock of Peter's confession we call according to the decree of the Savior the universal Church, wherein we must remain for the salvation of our souls and wherein loyal to his faith and confession we must obey him."
(Against the Errors of the Greeks, Pt. 2, ch. 36)
Let’s Raise a Glass to the Bad Popes!
"It may seem odd, on the feast day of the Roman Fact, to discuss the less-than-stellar occupants of the Chair of Peter. I would propose that it is precisely these weak and sometimes sordid men who offer one of the most startling historical and apologetical claims for the indefectibility of the church. Catholics ought not to be reticent or ashamed about such men. A frank analysis of their weaknesses shows that often the Church survives in spite of the papacy, while the office endures as a witness to the seamless garment of Church tradition.
The demerits of some of the popes can be broken down into three categories: the inept, the imprudent, and the immoral. It is astonishing among the 265 holders of the office that so few can be charged with any of these (indeed around a third of all popes are recognized as saints). Nonetheless they are to be found; weaklings who refused to teach when teaching was necessary, spectacularly imprudent miscalculators, and downright seedy and Augean characters..."
Well if we’re going to talk about objective realities, those of you who reject the Vicar of Christ’s magisterium (Vatican II), discipline (1983 Code of Canon Law) and liturgy (the Novus Ordo) are schismatic.