The New Testament contains five different metaphors for the foundation of the Church (cf. Matt. 16:18; 1 Cor. 3:11; Eph. 2:20; 1 Pet. 2:5–6; Rev. 21:14). One metaphor that has been disputed is Jesus Christ’s calling the apostle Peter "rock": "You are Peter, and on this rock I will build my Church, and the powers of death shall not prevail against it" (Matt. 16:18).
Some argue that in this passage there is a minor difference between the Greek term for "Peter" (Petros) and the term for "rock" (petra), yet they ignore the obvious explanation: petra, a feminine noun, has been modified to have a masculine ending, since one would not refer to a man (Peter) as feminine. The change in the gender is purely for stylistic reasons.
These critics also neglect the fact that Jesus spoke Aramaic, and, as John 1:42 tells us, in everyday life he actually referred to Peter as Kepha or Cephas (depending on how it is transliterated). It is that term that is then translated into Greek as Petros. Thus, what Jesus actually said to Peter in Aramaic was: "You are Kepha, and on this kepha I will build my Church."
The Church Fathers, those Christians closest to the apostles in time, culture, and theological background, clearly understood that Jesus promised to build the Church on Peter, as the following passages show.
Simon Cephas answered and said, "You are the Messiah, the Son of the living God." Jesus answered and said unto him, "Blessed are you, Simon, son of Jonah: flesh and blood has not revealed it unto thee, but my Father which is in heaven. And I say unto thee also, that you are Cephas, and on this rock will I build my Church; and the gates of hades shall not prevail against it" (The Diatesseron 23 [A.D. 170]).
Was anything withheld from the knowledge of Peter, who is called "the rock on which the Church would be built" [Matt. 16:18] with the power of "loosing and binding in heaven and on earth" [Matt. 16:19]? (Demurrer against the Heretics 22 [A.D. 200]).
The Lord said to Peter, "On this rock I will build my Church, I have given you the keys of the kingdom of heaven [and] whatever you shall have bound or loosed on earth will be bound or loosed in heaven" [Matt. 16:18–19]. . . . What kind of man are you, subverting and changing what was the manifest intent of the Lord when he conferred this personally upon Peter? Upon you, he says, I will build my Church; and I will give to you the keys (Modesty 21:9–10 [A.D. 220]).
Look at [Peter], the great foundation of the Church, that most solid of rocks, upon whom Christ built the Church [cf. Matt. 16:18]. And what does our Lord say to him? "Oh you of little faith," he says, "why do you doubt?" [Matt. 14:31] (Homilies on Exodus 5:4 [A.D. 248]).
The Lord says to Peter: "I say to you," he says, "that you are Peter, and upon this rock I will build my Church, and the gates of hell will not overcome it. And to you I will give the keys of the kingdom of heaven" [Matt. 16:18–19]. On him [Peter] he builds the Church, and to him he gives the command to feed the sheep [cf. John 21:17], and although he assigns a like power to all the apostles, yet he founded a single chair [cathedra], and he established by his own authority a source and an intrinsic reason for that unity. Indeed, the others were that also which Peter was [i.e., apostles], but a primacy is given to Peter, whereby it is made clear that there is but one Church and one chair. . . . If someone does not hold fast to this unity of Peter, can he imagine that he still holds the faith? If he [should] desert the chair of Peter upon whom the Church was built, can he still be confident that he is in the Church? (The Unity of the Catholic Church 4; 1st edition [A.D. 251]).
There is one God and one Christ, and one Church, and one chair founded on Peter by the word of the Lord. It is not possible to set up another altar or for there to be another priesthood besides that one altar and that one priesthood. Whoever has gathered elsewhere is scattering (Letters 43:5 [A.D. 253]).
There [John 6:68–69] speaks Peter, upon whom the Church would be built, teaching in the name of the Church and showing that even if a stubborn and proud multitude withdraws because it does not wish to obey, yet the Church does not withdraw from Christ. The people joined to the priest and the flock clinging to their shepherd are the Church. You ought to know, then, that the bishop is in the Church and the Church in the bishop, and if someone is not with the bishop, he is not in the Church. They vainly flatter themselves who creep up, not having peace with the priests of God, believing that they are secretly [i.e., invisibly] in communion with certain individuals. For the Church, which is one and Catholic, is not split nor divided, but it is indeed united and joined by the cement of priests who adhere one to another (ibid., 66:8).
[Pope] Stephen [I] . . . boasts of the place of his episcopate, and contends that he holds the succession from Peter, on whom the foundations of the Church were laid [cf. Matt. 16:18]. . . . [Pope] Stephen . . . announces that he holds by succession the throne of Peter (collected in Cyprian’s Letters 74:17).
[Jesus said:] "Simon, my follower, I have made you the foundation of the holy Church. I betimes called you Peter, because you will support all its buildings. You are the inspector of those who will build on earth a Church for me. If they should wish to build what is false, you, the foundation, will condemn them. You are the head of the fountain from which my teaching flows; you are the chief of my disciples" (Homilies 4:1 [A.D. 351]).
You cannot deny that you are aware that in the city of Rome the episcopal chair was given first to Peter; the chair in which Peter sat, the same who was head—that is why he is also called Cephas ["Rock"]—of all the apostles; the one chair in which unity is maintained by all (The Schism of the Donatists 2:2 [A.D. 367]).
Ambrose of Milan
[Christ] made answer: "You are Peter, and upon this rock will I build my Church." Could he not, then, strengthen the faith of the man to whom, acting on his own authority, he gave the kingdom, whom he called the rock, thereby declaring him to be the foundation of the Church [cf. Matt. 16:18]? (The Faith 4:5 [A.D. 379]).
It is to Peter that he says: "You are Peter, and upon this rock I will build my Church" [Matt. 16:18]. Where Peter is, there is the Church. And where the Church is, no death is there, but life eternal (Commentary on Twelve Psalms of David 40:30 [A.D. 389]).
Pope Damasus I
Likewise it is decreed . . . that it ought to be announced that . . . the holy Roman Church has not been placed at the forefront [of the churches] by the conciliar decisions of other churches but has received the primacy by the evangelic voice of our Lord and Savior, who says: "You are Peter, and upon this rock I will build my Church, and the gates of hell will not prevail against it; and I will give to you the keys of the kingdom of heaven." [Matt. 16:18–19]. The first see, therefore, is that of Peter the apostle, that of the Roman Church, which has neither stain nor blemish nor anything like it (Decree of Damasus 3 [A.D. 382]).
"But," you [Jovinian] will say, "it was on Peter that the Church was founded" [Matt. 16:18]. Well . . . one among the twelve is chosen to be their head in order to remove any occasion for division (Against Jovinian 1:26 [A.D. 393]).
I follow no leader but Christ and join in communion with none but your blessedness [Pope Damasus I], that is, with the chair of Peter. I know that this is the rock on which the Church has been built. Whoever eats the Lamb outside this house is profane. Anyone who is not in the ark of Noah will perish when the flood prevails (Letters 15:2 [A.D. 396]).
If the very order of episcopal succession is to be considered, how much more surely, truly, and safely do we number them [the bishops of Rome] from Peter himself, to whom, as to one representing the whole Church, the Lord said, "Upon this rock I will build my Church, and the gates of hell shall not conquer it." Peter was succeeded by Linus, Linus by Clement. . . . In this order of succession a Donatist bishop is not to be found (Letters 53:1:2 [A.D. 412]).
Sechnall of Ireland
Steadfast in the fear of God, and in faith immovable, upon [Patrick] as upon Peter the [Irish] church is built; and he has been allotted his apostleship by God; against him the gates of hell prevail not (Hymn in Praise of St. Patrick 3 [A.D. 444]).
Pope Leo I
Our Lord Jesus Christ . . . has placed the principal charge on the blessed Peter, chief of all the apostles. . . . He wished him who had been received into partnership in his undivided unity to be named what he himself was, when he said: "You are Peter, and upon this rock I will build my Church" [Matt. 16:18], that the building of the eternal temple might rest on Peter’s solid rock, strengthening his Church so surely that neither could human rashness assail it nor the gates of hell prevail against it (Letters 10:1 [A.D. 445]).<