St. Peter, the fervent follower of Jesus Christ, for the profound confession of His Divinity: "Thou art the Christ, the Son of the Living God," was deemed worthy by the Savior to hear in answer, "Blessed art thou, Simon ... I tell thee, that thou art Peter [Petrus], and on this stone [petra] I build My Church" (Mt.16:16-18). On "this stone" [petra], is on that which thou sayest: "Thou art the Christ, the Son of the Living God" it is on this thy confession I build My Church. Wherefore the "thou art Peter": it is from the "stone" [petra] that Peter [Petrus] is, and not from Peter [Petrus] that the "stone" [petra] is, just as the Christian is from Christ, and not Christ from the Christian. Do you want to know, from what sort of "rock" [petra] the Apostle Peter [Petrus] was named? Hear the Apostle Paul: "Brethren, I do not want ye to be ignorant," says the Apostle of Christ, "how all our fathers were all under the cloud, and all passed through the sea; and all were baptized unto Moses in the cloud and in the sea; and did all drink the same spiritual drink: for they drank of that spiritual Rock that followed them: and that Rock was Christ" (1 Cor.10: 1-4). Here is the from whence the "Rock" is Peter.
Our Lord Jesus Christ, in the final days of His earthly life, in the days of His mission to the race of man, chose from among the disciples His twelve Apostles to preach the Word of God. Among them, the Apostle Peter for his fiery ardor was vouchsafed to occupy the first place (Mt.10:2) and to be as it were the representative person for all the Church. Therefore it is said to him, preferentially, after the confession: "I will give unto thee the keys of the Kingdom of Heaven: and whatsoever thou shalt bind on earth, shall be bound in the heaven: and whatsoever thou shalt loose on earth: shall be loosed in heaven" (Mt.16: 19). Therefore it was not one man, but rather the One Universal Church, that received these "keys" and the right "to bind and loosen." And that it was actually the Church that received this right, and not exclusively a single person, turn your attention to another place of the Scriptures, where the same Lord says to all His Apostles, "Receive ye the Holy Spirit" and further after this, "Whose soever sins ye remit, they are remitted unto them: and whose soever sins ye retain, are retained" (John 20: 22-23); or: "whatsoever ye bind upon the earth, shall be bound in Heaven: and whatsoever ye shall loose on earth, shall be loosened in heaven" (Mt.18:18). Thus, it is the Church that binds, the Church that loosens; the Church, built upon the foundational cornerstone, Jesus Christ Himself (Eph 2:20), doth bind and loosen. Let both the binding and the loosening be feared: the loosening, in order not to fall under this again; the binding, in order not to remain forever in this condition. Therefore "Iniquities ensnare a man, and everyone is bound in the chains of his own sins," says Wisdom (Prov 5:22); and except for Holy Church nowhere is it possible to receive the loosening.
After His Resurrection the Lord entrusted the Apostle Peter to shepherd His spiritual flock not because, that among the disciples only Peter alone was pre-deserved to shepherd the flock of Christ, but Christ addresses Himself chiefly to Peter because, that Peter was first among the Apostles and as such the representative of the Church; besides which, having turned in this instance to Peter alone, as to the top Apostle, Christ by this confirms the unity of the Church. "Simon of John" -- says the Lord to Peter -- "lovest thou Me?" -- and the Apostle answered: "Yea, Lord, Thou knowest that I love Thee"; and a second time it was thus asked, and a second time he thus answered; being asked a third time, seeing that as it were not believed, he was saddened. But how is it possible for him not to believe That One, Who knew his heart? And wherefore then Peter answered: "Lord, Thou knowest all; Thou knowest that I love Thee." "And sayeth Jesus to him" all three times "Feed My sheep" (John 20:15-17).
Besides this, the triple appealing of the Savior to Peter and the triple confession of Peter before the Lord had a particular beneficial purpose for the Apostle. That one, to whom was given "the keys of the kingdom" and the right "to bind and to loose," bound himself thrice by fear and cowardice (Mt.26:69-75), and the Lord thrice loosens him by His appeal and in turn by his confession of strong love. And to shepherd literally the flock of Christ was acquired by all the Apostles and their successors. "Take heed, therefore unto yourselves, and to all the flock," the Apostle Paul urges church presbyters, "over which the Holy Spirit hath made you overseers, to feed the Church of the God, which He hath purchased with His own blood" (Acts 20:28); and the Apostle Peter to the elders: "Feed the flock of God which is among you, taking the oversight thereof not by constraint, but willingly: not for filthy lucre, but of a ready mind: neither as being lords over God's heritage, but being examples to the flock. And when is appeared the Prince of pastors, ye will receive unfading crowns of glory" (1 Pet. 5:2-4).
It is remarkable that Christ, having said to Peter: "Feed My sheep," did not say: "Feed thy sheep," but rather to feed, good servant, the sheep of the Lord. "Is Christ divided? was Paul crucified for you? or were ye baptized in the name of Paul?" (1 Cor.1:13). "Feed My sheep". Wherefore "wolfish robbers, wolfish oppressors, deceitful teachers and mercenaries, not being concerned about the flock" (Mt.7:15; Acts 20:29; 2 Pet 2:1; John 10:12), having plundered a strange flock and making of the spoils as though it be of their own particular gain, they think that they feed their flock. Such are not good pastors, as pastors of the Lord. "The good shepherd giveth his life for the sheep" (John 10:11), entrusted to Him by the chief Shepherd Himself (1 Pet 5:4). And the Apostle Peter, true to his calling, gave his soul for the very flock of Christ, having sealed his apostleship by a martyr's death, is now glorified throughout all the world.
The Apostle Paul, formerly Saul, was changed from a robbing wolf into a meek lamb. Formerly he was an enemy of the Church, then is manifest as an Apostle. Formerly he stalked it, then preached it. Having received from the high priests the authority at large to throw all Christians in chains for execution, he was already on the way, he breathed out "threatenings and slaughter against the disciples of the Lord" (Acts 9:1), he thirsted for blood, but "He that dwells in the Heavens shall laugh him to scorn" (Ps 2:4). When he, "having persecuted and vexed" in such manner "the Church of God" (1Cor.15:9; Acts 8:5), he came near Damascus, and the Lord from Heaven called to him: "Saul, Saul, why persecutest thou Me?" and I am here, and I am there, I am everywhere: here is My head; there is My body. There becomes nothing of a surprise in this; we ourselves are members of the Body of Christ. "Saul, Saul, why persecutest thou Me; it is hard for thee to kick against the goad" (Acts 9:4-5). Saul, however, "trembling and frightened", cried out: "Who art Thou, Lord?" The Lord answered him, "I am Jesus Whom thou persecutest."
And Saul suddenly undergoes a change: "What wantest Thou me to do?" -- he cries out. And suddenly for him there is the Voice: "Arise, and go to the city, and it shall be told thee what thou must do" (Acts 9:6). Here the Lord sends Ananias: "Arise and go into the street" to a man, "by the name of Saul," and baptize him, "for this one is a chosen vessel unto Me, to bear My name before the Gentiles, and kings, and the children of Israel" (Acts 9: 11, 15, 18). This vessel must be filled with My Grace. "Ananias, however, answered: Lord, I have heard from many about this man, how much evil he hath done to Thy saints in Jerusalem: and here he hath authority from the chief priests to bind all who call on Thy Name" (Acts 9:13-14). But the Lord urgently commands Ananias: "Search for and fetch him, for this vessel is chosen by Me: for I shall show him what great things he must suffer for My name's sake" (Acts 9:11, 15-16).
And actually the Lord did show the Apostle Paul what things he had to suffer for His Name. He instructed him the deeds; He did not stop at the chains, the fetters, the prisons and shipwrecks; He Himself felt for him in his sufferings, He Himself guided him towards this day. On a single day the memory of the sufferings of both these Apostles is celebrated, though they suffered on separate days, but by the spirit and the closeness of their suffering they constitute one. Peter went first, and Paul followed soon after him. Formerly called Saul, and then Paul, having transformed his pride into humility. His very name (Paulus), meaning "small, little, less," demonstrates this. What is the Apostle Paul after this? Ask him, and he himself gives answer to this: "I am," says he, "the least of the Apostles... but I have labored more abundantly than all of them: yet not I, but the grace of God, which was with me" (1 Cor.15:9-10).
And so, brethren, celebrating now the memory of the holy Apostles Peter and Paul, remembering their venerable sufferings, we esteem their true faith and holy life, we esteem the innocence of their sufferings and pure confession. Loving in them the sublime quality and imitating them by great exploits, "in which to be likened to them" (2 Thess 3: 5-9), and we shall attain to that eternal bliss which is prepared for all the saints. The path of our life before was more grievous, thornier, harder, but "we also are compassed about with so great a cloud of witnesses" (Heb 12: 1), having passed by along it, made now for us easier, and lighter, and more readily passable. First there passed along it "the author and finisher of our faith," our Lord Jesus Christ Himself (Heb 12: 2); His daring Apostles followed after Him; then the martyrs, children, women, virgins and a great multitude of witnesses. Who acted in them and helped them on this path? He Who said, "Without Me ye can do nothing" (John 15: 5)."
(http://ocafs.oca.org/FeastSaintsViewer.asp?SID=4&ID=1&FSID=101840)