But how do we know that the Holy Spirit’s protection of the Church from error is unique from any other institution? We rely on what God has revealed to us, through Sacred Scripture and through Sacred Tradition. When Christ gives St. Peter the keys to the Kingdom of Heaven, He promises that whatever Peter binds “on earth shall be bound in heaven, and whatever [he] loose[s] on earth shall be loosed in heaven” (Mt 16:19). By giving St. Peter the keys, Christ is fulfilling something described in Isaiah 22, when the Lord gives keys to Eliakim when he appoints him the prime minister of Israel, and that whatever “he shall open, and none shall shut; and he shall shut, and none shall open” (Is 22:22). The closely mirrored language between Isaiah and Matthew gives strong evidence for the papacy, and specifically for papal succession. The office of prime minister, like that of the papacy, is not a one-and-done office, but an ongoing role with successors. Likewise, the successors, upon becoming prime ministers, receive the authority of the office. Thus, Christ gives St. Peter’s authority to bind and loose, and with him, his successors as well. Moreover, this key is the “key of the house of David” (Is 22:22). When He became incarnate, our Lord Jesus Christ was born in the line of David, fulfilling the Davidic prophecy that the Messiah would be born in the line of David. Thus, Christ receives the keys of David from the Lord by His taking human flesh in the line of David. Therefore, He can give them to St. Peter. However, since He is God, the Lord did not give up authority by giving the keys to Eliakim, and so He does not lose authority by giving the keys to St. Peter, but in fact shares and augments His authority by drawing attention to His vast generosity.
Some will object to papal succession, claiming that Christ gave only Peter power to govern His Church, and that this authority ended with St. Peter’s death, and that all Christians after him ought to be subject to Christ alone. But even though we are subject to the pope, we, in the end, are subject to Christ alone because even the pope is subject to Christ. All authority that the pope has, he has received from God. “If then you received it, why do you boast as if it were not a gift?” (1 Cor 4:7).
But the claim that the authority Christ gave to St. Peter ended with St. Peter’s death is not plausible. “And I tell you, you are Peter, and on this rock I will build my church, and the powers of death shall not prevail against it” (Mt 16:18). The Church cannot exist if the rock does not support it, for then it would be built on sand, and thus would be “completely destroyed” in the trials of life (Lk 6:49). If the Church no longer exists, then Christ was wrong, or He lied to us. But this is absurd. Christ is the Truth personified, so He cannot err, nor can He deny Himself.
Another objection to the Church’s authority is that since when Christ refers to Peter He uses the word petros, while when He refers to the rock upon which He will build His Church He uses petra, the petra refers not to the petros, but either to St. Peter’s confession of faith or to Christ Himself. But even many Protestant scholars and theologians, such as John Broadus, Craig S. Keener, D.A. Carson, and Dr. Oscar Cullman, assert that Peter is indeed the rock, not Christ, nor Peter’s confession, and that it is either far-fetched or virtually meaningless to say the rock is Christ, or St. Peter’s confession of faith, respectively. One cannot build a Church upon an act (of faith). Rather, a Church, as any institution, must be built upon something or someone. Moreover, to say that the church is built upon Peter does not mean that Christ does not rule His Church. Rather, St. Peter and his successors are Christ’s vicars on earth. For example, even though the Blessed Virgin Mary was the spouse of the Holy Spirit, the Holy Spirit would not protect her from a mob attempting to stone her to death for (appearing to) commit adultery. Thus, the Lord chose St. Joseph to protect Mary from these and similar things, as well as to raise the Son of God. Christ will not always directly protect His spouse, the Church, in a physical way, Rather, He appoints a “St. Joseph” to protect her from those who try to injure her. Likewise, Christ gives popes the authority to raise the Church, so to speak, by exercising their God-given power to bind and loose (i.e. to make decisions which we must obey). The builder is greater than the building, and the building does not detract from the builder in any way, but only glorifies Him by revealing his craftsmanship.
Yet another objection to this power may be that because Christ gave all the apostles the power to bind and loose (see Mt 18:18), there is no central authority whom we must obey. It is true that Christ gave all the apostles the power to bind and loose. The Church still abides by this decision, meaning that all the Church’s bishops (the successors of the apostles), not just the Bishop of Rome, have the authority to enforce rules that “bind” the people of God to assent to something. However, while Christ gave all the apostles the power to bind and loose, He only gave the keys to St. Peter, and therefore only gave St. Peter supreme authority of the Church. Again, recall Isaiah 22:22: “I will place on his shoulder the key of the house of David; he shall open, and none shall shut; and he shall shut, and none shall open” (Is 22:22). When the Lord gives the keys to Eliakim, he gives Eliakim supreme authority over Judea. Also, Eliakim takes the office of prime minister, meaning that he will have successors. Being a prime minister is not a one and done job. Likewise, the papacy is not a one and done job, but continuing office.
Further, Christ does give all the apostles authority in Mt 18:18, but does so in context of the Church. When taken in context, this verse comes directly after Christ instructs His apostles how they must admonish a sinner: “If your brother sins against you, go and tell him his fault, between you and him alone… But if he does not listen, take one or two others along with you, that every word may be confirmed by the evidence of two or three witnesses. If he refuses to listen to them, tell it to the church; and if he refuses to listen even to the church, let him be to you as a Gentile and a tax collector. Truly, I say to you, whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven” (Mt 18:15-18). The Church has the final word in all these disputes. Therefore, if men listen to the Church, they are reconciled with Christ, but if they do not, they are anathema.
A non-Christian may raise the objection that scripture is just a bunch of holy-sounding words that early bishops compiled so that they could claim that God the Holy Spirit protected them from error. Likewise, they fabricated arbitrary rules such as teachings that Divine Revelation ended with the death of the last apostle, so that they could prevent anyone from proclaiming new Divine Revelation that conflicted with the Bible’s claims about their authority.
Without Sacred Tradition, it may be difficult to refute these objections. But Sacred Tradition captures the big picture, such as the effect of Christ’s Passion, Death, and Resurrection on mankind, the sincerity of the apostles (they traveled around the world spreading the Gospel and 11 of them suffered martyrdom for the Faith), the fact that the earliest Christians believed immediately after the apostles began evangelizing, the immense success of Christianity against numerous difficulties, the intellectual prowess of some the Church’s greatest saints, etc. The Church compiled the Canon of Scripture and taught what she teaches regarding everything, including the timeline and method(s) of transmission of Divine Revelation, based on how Divine Revelation had been communicated through Sacred Tradition. In fact, the Canon of Scripture was not complete until the Council of Rome, in A.D. 382, when Pope St. Damasus I approved the final composition of Scripture we know it today (Catholic Exchange).
The pope, along with the bishops of the universal Church, received the power to bind and loose from Christ, not from scripture. Therefore, for Pope St. Damasus I to compile the final list of Sacred Scripture, he did not need scripture. These books had been around for at least close to a few hundred years or more, but the bishops’ teaching authority still did not come from the writings, but from Christ Himself. Christ did not command His apostles to write, but to do. Therefore, Catholic bishops, guided by the Holy Spirit, determined what constituted Sacred Scripture by the Holy Spirit, who works through Sacred Tradition. Early Christians also recognized this fact. Even though they had no definitive New Testament compilation of books yet, they acknowledged the pope’s supreme authority, and thus heis and his fellow bishops’ power to bind and loose. It was fitting that the apostles and other holy authors, inspired by the Holy Spirit, should write down what they saw, heard, and did, for the sake of mankind’s sanctification. However, this was not necessary. Not all saints have to be bible scholars, but they must live the bible, especially the gospel, message. Therefore, the doctrine of Sola Scriptura makes no sense. Scripture cannot be treated apart from the Church’s authority, lest it be misinterpreted.