"Upon this rock" Is 22:19-23; Ps 138:1-2, 2-3, 6, 8; Rom 11:33-36; Mt 16:13-20 The readings for this Sunday point to something that is uniquely Catholic: the pope. The anchor of all this is the famous passage from Matthew’s Gospel where Jesus gives Peter a special blessing and commission. When Jesus and his disciples go into the region of Caesarea Philippi, a site currently near the border with Lebanon, he asks the most probing question of the Gospel: “Who do you say that I am?” The disciples run through some possibilities that others have raised, “Some say John the Baptist, others Elijah, still others Jeremiah or one of the prophets.” Each choice reflects the reputation of Jesus as a powerful prophet. But it is Simon Peter who gives the right answer: “You are the Christ, the Son of God.” Peter acclaims Jesus as the promised Messiah, the Christ or anointed one, and even more profoundly, as the “Son of God,” a title that identifies Jesus as a royal figure (the kings of Israel were also called “sons of God”). In the Gospels, this also signals Jesus’ unique intimacy with God, as one who embodies the divine presence. Because Peter’s answer is a profound act of faith, itself a gift of God, he receives an extraordinary blessing. Peter is commissioned by Jesus to be the “rock” (a play on the Greek name “Petros”) on which the church of Jesus will be built. And Peter will have authority — holding the “keys of the kingdom” and the power of “binding and loosing” — an apparent metaphor for deciding who belongs to the community of faith. The first reading from Isaiah provides an Old Testament backdrop for this scene. Isaiah predicts that Shebna, the unfaithful master of the king’s palace, will be deposed and in his place the Lord will appoint Eliakim, son of Hilkiah, who will be a “father” to the people, who will faithfully guard the door, and be placed in a position of honor “like a peg in a sure spot.” Catholic tradition has seen in this Matthean passage the biblical justification for the Petrine ministry, that office of unity that is meant to strengthen the church in its faith and be a guarantee of the church’s fidelity to the teaching of Jesus. The New Testament honors Peter for sure: among the first of the disciples chosen by Jesus; the first to encounter the Risen Christ; the one who accepts into the community the first Gentile convert, Cornelius the Roman centurion of Caesarea Maritima; the one who leads the Jerusalem church in confirming the mission of Paul to the Gentiles; one whom Jesus in John’s Gospel tells to “feed my lambs, tend to my sheep”; and one whom early tradition remembers as a martyr for his master. At the same time, the New Testament refuses to idealize Peter. His weaknesses and failings match his honors. Matthew’s Gospel in particular, stresses this. Peter sinks beneath the waves because he is of “little faith” — only the hand of Jesus rescues him. Right after making his bold confession of faith, Peter chides Jesus for speaking of his passion — earning from Jesus a sharp rebuke, “Get behind me, Satan!” And who can forget the abject failure of Peter at the hour of Jesus’ greatest need denying with an oath, that he even knew Jesus? No one could doubt that Peter was a fallible human being, as his successors would be. More than anything else, the successors of Peter are meant to exemplify what faithful discipleship in any age is meant to be. In the long history of the papacy, there have been abject failures. In recent years, though, the church has been blessed with popes who are truly Christian. They are still human and not every Catholic is equally enthusiastic about a particular pope. But the modern popes have been faithful, a credible sign of unity for a global church. Each has reminded us, as our current pope does so eloquently, of the need for justice for the poor and the unquenching search for peace. At a time when a fractured and frightened world thirsts for credible moral leaders and signs of unity, we give thanks for the successors of Peter.