Today we celebrate the memory of the Holy, Glorious, and All-Praised Leaders of the Apostles Peter and Paul.
The Blessed Augustine of Hippo, in a homily for today's feast, says:
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.Today's feast, then, is a celebration of the Church's unity. Anyone who has read Acts or Galatians, however, will recall that Saints Peter and Paul did not always think or act in perfect harmony. Concerning their dispute about the application of the Law to Gentiles, for instance, Saint Paul writes: when Peter was come to Antioch, I withstood him to his face, because he was to be blamed (Gal 2:11). Nor did the Apostles always see eye-to-eye on monetary questions. At times I am tempted to think that the disunity of the Church militant is just as much a fundamental attribute of the Church as is the unity of the Church triumphant. This thought in fact serves as something of a comfort when faced with the scandals we manage to create in the Church day in and day out.
The liturgical service in honor of Saints Peter and Paul can be read here.