The Vicar of Christ:
The papacy is the term for the office and the authority of the pope of Rome, the successor to Saint Peter as bishop of Rome and head of the universal Church. Also called “the pontiff,” “the Holy Father,” and “the Vicar of Christ,” the pope is the spiritual head of all Christendom and a visible symbol of unity in the Church.
First Among Equals
The understanding of the papacy has changed over time, as the Church has come to recognize the importance of the role. Once regarded simply as the primus inter pares, the “first among equals,” the pope of Rome, by virtue of being the successor to Saint Peter, the first of the apostles, was seen as worthy of the greatest respect of any of the bishops of the Church. From this emerged the idea of the pope as arbiter of disputes, and very early in Church history, other bishops began appealing to Rome as the center of orthodoxy in doctrinal arguments.
The seeds for this development were there from the beginning, however. In Matthew 16:15, Christ asked his disciples: “Who do you say that I am?” When Peter replied, “You are the Christ, the Son of the living God,” Jesus told Peter that this had been revealed to him not by man, by God the Father.
Peter’s given name was Simon, but Christ told him, “You are Peter”—a Greek word which means “rock”—“and upon this rock I will build my Church. And the gates of Hell will not prevail against it.” From this comes the Latin phrase Ubi Petrus, ibi ecclesia: Wherever Peter is, there is the Church.
The Role of the Pope:
That visible symbol of unity is an assurance to the Catholic faithful that they are members of the one holy catholic and apostolic Church founded by Christ. But the pope is also the chief administrator of the Church. He appoints bishops and the cardinals, who will elect his successor. He is the final arbiter of both administrative and doctrinal disputes.
While doctrinal matters are normally resolved by an ecumenical council (a meeting of all of the bishops of the Church), such a council can only be called by the pope, and its decisions are not official until confirmed by the pope.
One such council, the First Vatican Council of 1870, recognized the doctrine of papal infallibility. While some non-Catholic Christians regard this as a novelty, this doctrine is simply a full understanding of Christ’s response to Peter, that it was God the Father who revealed to him that Jesus was the Christ.
Papal infallibility does not mean that the pope can never do anything wrong. However, when, like Peter, he is speaking on matters of faith and morals and intends to instruct the whole Church by defining a doctrine, the Church believes that he is protected by the Holy Spirit and cannot speak in error.
The Invocation of Papal Infallibility:
The actual invocation of papal infallibility has been very limited. In recent times, only two popes have declared doctrines of the Church, both having to do with the Virgin Mary: Pius IX, in 1854, declared theImmaculate Conception of Mary (the doctrine that Mary was conceived without the stain of Original Sin); and Pius XII, in 1950, declared that Mary had been assumed into Heaven bodily at the end of her life (the doctrine of the Assumption).
The Papacy in the Modern World:
Despite concerns about the doctrine of papal infallibility, both some Protestants and some Eastern Orthodox have expressed, in recent years, a growing interest in the institution of the papacy. They recognize the desirability of a visible head of all Christians, and they have a deep respect for the moral force of the office, especially as exercised by such recent popes as John Paul II and Benedict XVI.
Still, the papacy is one of the greatest stumbling blocks to the reunification of the Christian churches. Because it is essential to the nature of the Catholic Church, having been instituted by Christ himself, it cannot be abandoned. Instead, Christians of good will of all denominations need to engage in a dialogue to come to a deeper understanding of how the papacy was meant to unite us, rather than divide us.
From Catholic.com website:
Peter and the Papacy
There is ample evidence in the New Testament that Peter was first in authority among the apostles. Whenever they were named, Peter headed the list (Matt. 10:1-4, Mark 3:16-19, Luke 6:14-16, Acts 1:13); sometimes the apostles were referred to as “Peter and those who were with him” (Luke 9:32). Peter was the one who generally spoke for the apostles (Matt. 18:21, Mark 8:29, Luke 12:41, John 6:68-69), and he figured in many of the most dramatic scenes (Matt. 14:28-32, Matt. 17:24-27, Mark 10:23-28). On Pentecost it was Peter who first preached to the crowds (Acts 2:14-40), and he worked the first healing in the Church age (Acts 3:6-7). It is Peter’s faith that will strengthen his brethren (Luke 22:32) and Peter is given Christ’s flock to shepherd (John 21:17). An angel was sent to announce the resurrection to Peter (Mark 16:7), and the risen Christ first appeared to Peter (Luke 24:34). He headed the meeting that elected Matthias to replace Judas (Acts 1:13-26), and he received the first converts (Acts 2:41). He inflicted the first punishment (Acts 5:1-11), and excommunicated the first heretic (Acts 8:18-23). He led the first council in Jerusalem (Acts 15), and announced the first dogmatic decision (Acts 15:7-11). It was to Peter that the revelation came that Gentiles were to be baptized and accepted as Christians (Acts 10:46-48).
Peter the Rock
Peter’s preeminent position among the apostles was symbolized at the very beginning of his relationship with Christ. At their first meeting, Christ told Simon that his name would thereafter be Peter, which translates as “Rock” (John 1:42). The startling thing was that—aside from the single time that Abraham is called a “rock” (Hebrew: Tsur; Aramaic: Kepha) in Isaiah 51:1-2—in the Old Testament only God was called a rock. The word rock was not used as a proper name in the ancient world. If you were to turn to a companion and say, “From now on your name is Asparagus,” people would wonder: Why Asparagus? What is the meaning of it? What does it signify? Indeed, why call Simon the fisherman “Rock”? Christ was not given to meaningless gestures, and neither were the Jews as a whole when it came to names. Giving a new name meant that the status of the person was changed, as when Abram’s name was changed to Abraham (Gen.17:5), Jacob’s to Israel (Gen. 32:28), Eliakim’s to Joakim (2 Kgs. 23:34), or the names of the four Hebrew youths—Daniel, Hananiah, Mishael, and Azariah to Belteshazzar, Shadrach, Meshach, and Abednego (Dan. 1:6-7). But no Jew had ever been called “Rock.” The Jews would give other names taken from nature, such as Deborah (“bee,” Gen. 35:8), and Rachel (“ewe,” Gen. 29:16), but never “Rock.” In the New Testament James and John were nicknamed Boanerges, meaning “Sons of Thunder,” by Christ, but that was never regularly used in place of their original names, and it certainly was not given as a new name. But in the case of Simon-bar-Jonah, his new name Kephas (Greek: Petros) definitely replaced the old.
Promises to Peter
When he first saw Simon, “Jesus looked at him, and said, ‘So you are Simon the son of John? You shall be called Cephas (which means Peter)’” (John 1:42). The word Cephas is merely the transliteration of the Aramaic Kepha into Greek. Later, after Peter and the other disciples had been with Christ for some time, they went to Caesarea Philippi, where Peter made his profession of faith: “You are the Christ, the Son of the living God” (Matt. 16:16). Jesus told him that this truth was specially revealed to him, and then he solemnly reiterated: “And I tell you, you are Peter” (Matt. 16:18). To this was added the promise that the Church would be founded, in some way, on Peter (Matt. 16:18).
Then two important things were told the apostle. “Whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven” (Matt. 16:19). Here Peter was singled out for the authority that provides for the forgiveness of sins and the making of disciplinary rules. Later the apostles as a whole would be given similar power [Matt.18:18], but here Peter received it in a special sense.
Peter alone was promised something else also: “I will give you the keys of the kingdom of heaven” (Matt. 16:19). In ancient times, keys were the hallmark of authority. A walled city might have one great gate; and that gate had one great lock, worked by one great key. To be given the key to the city—an honor that exists even today, though its import is lost—meant to be given free access to and authority over the city. The city to which Peter was given the keys was the heavenly city itself. This symbolism for authority is used elsewhere in the Bible (Is. 22:22, Rev. 1:18).
Finally, after the resurrection, Jesus appeared to his disciples and asked Peter three times, “Do you love me?” (John 21:15-17). In repentance for his threefold denial, Peter gave a threefold affirmation of love. Then Christ, the Good Shepherd (John 10:11, 14), gave Peter the authority he earlier had promised: “Feed my sheep” (John 21:17). This specifically included the other apostles, since Jesus asked Peter, “Do you love me more than these?” (John 21:15), the word “these” referring to the other apostles who were present (John 21:2). Thus was completed the prediction made just before Jesus and his followers went for the last time to the Mount of Olives.
Immediately before his denials were predicted, Peter was told, “Simon, Simon, behold, Satan demanded to have you, that he might sift you like wheat, but I have prayed for you that your faith may not fail; and when you have turned again [after the denials], strengthen your brethren” (Luke 22:31-32). It was Peter who Christ prayed would have faith that would not fail and that would be a guide for the others; and his prayer, being perfectly efficacious, was sure to be fulfilled.
Who is the rock?
Now take a closer look at the key verse: “You are Peter, and on this rock I will build my Church” (Matt. 16:18). Disputes about this passage have always been related to the meaning of the term “rock.” To whom, or to what, does it refer? Since Simon’s new name of Peter itself means rock, the sentence could be rewritten as: “You are Rock and upon this rock I will build my Church.” The play on words seems obvious, but commentators wishing to avoid what follows from this—namely the establishment of the papacy—have suggested that the word rock could not refer to Peter but must refer to his profession of faith or to Christ.
From the grammatical point of view, the phrase “this rock” must relate back to the closest noun. Peter’s profession of faith (“You are the Christ, the Son of the living God”) is two verses earlier, while his name, a proper noun, is in the immediately preceding clause.
As an analogy, consider this artificial sentence: “I have a car and a truck, and it is blue.” Which is blue? The truck, because that is the noun closest to the pronoun “it.” This is all the more clear if the reference to the car is two sentences earlier, as the reference to Peter’s profession is two sentences earlier than the term rock.
The previous argument also settles the question of whether the word refers to Christ himself, since he is mentioned within the profession of faith. The fact that he is elsewhere, by a different metaphor, called the cornerstone (Eph. 2:20, 1 Pet. 2:4-8) does not disprove that here Peter is the foundation. Christ is naturally the principal and, since he will be returning to heaven, the invisible foundation of the Church that he will establish; but Peter is named by him as the secondary and, because he and his successors will remain on earth, the visible foundation. Peter can be a foundation only because Christ is the cornerstone.
In fact, the New Testament contains five different metaphors for the foundation of the Church (Matt. 16:18, 1 Cor. 3:11, Eph. 2:20, 1 Pet. 2:5-6, Rev. 21:14). One cannot take a single metaphor from a single passage and use it to twist the plain meaning of other passages. Rather, one must respect and harmonize the different passages, for the Church can be described as having different foundations since the word foundation can be used in different senses.
Look at the Aramaic
Opponents of the Catholic interpretation of Matthew 16:18 sometimes argue that in the Greek text the name of the apostle is Petros, while “rock” is rendered as petra. They claim that the former refers to a small stone, while the latter refers to a massive rock; so, if Peter was meant to be the massive rock, why isn’t his name Petra?
Note that Christ did not speak to the disciples in Greek. He spoke Aramaic, the common language of Palestine at that time. In that language the word for rock is kepha, which is what Jesus called him in everyday speech (note that in John 1:42 he was told, “You will be called Cephas”). What Jesus said in Matthew 16:18 was: “You are Kepha, and upon this kepha I will build my Church.”
When Matthew’s Gospel was translated from the original Aramaic to Greek, there arose a problem which did not confront the evangelist when he first composed his account of Christ’s life. In Aramaic the word kepha has the same ending whether it refers to a rock or is used as a man’s name. In Greek, though, the word for rock, petra, is feminine in gender. The translator could use it for the second appearance of kepha in the sentence, but not for the first because it would be inappropriate to give a man a feminine name. So he put a masculine ending on it, and hence Peter became Petros.
Furthermore, the premise of the argument against Peter being the rock is simply false. In first century Greek the words petros and petra were synonyms. They had previously possessed the meanings of “small stone” and “large rock” in some early Greek poetry, but by the first century this distinction was gone, as Protestant Bible scholars admit (see D. A. Carson’s remarks on this passage in the Expositor’s Bible Commentary, [Grand Rapids: Zondervan Books]).
Some of the effect of Christ’s play on words was lost when his statement was translated from the Aramaic into Greek, but that was the best that could be done in Greek. In English, like Aramaic, there is no problem with endings; so an English rendition could read: “You are Rock, and upon this rock I will build my church.”
Consider another point: If the rock really did refer to Christ (as some claim, based on 1 Cor. 10:4, “and the Rock was Christ” though the rock there was a literal, physical rock), why did Matthew leave the passage as it was? In the original Aramaic, and in the English which is a closer parallel to it than is the Greek, the passage is clear enough. Matthew must have realized that his readers would conclude the obvious from “Rock . . . rock.”
If he meant Christ to be understood as the rock, why didn’t he say so? Why did he take a chance and leave it up to Paul to write a clarifying text? This presumes, of course, that 1 Corinthians was written after Matthew’s Gospel; if it came first, it could not have been written to clarify it.
The reason, of course, is that Matthew knew full well that what the sentence seemed to say was just what it really was saying. It was Simon, weak as he was, who was chosen to become the rock and thus the first link in the chain of the papacy.