The following extracts are taken from Pope Benedict XVI's homily for the Feast of Saints Peter and Paul, 29 June 2012, in St Peter's Basilica.
In front of Saint Peter's Basilica, as is well known, there are two imposing statues of Saint Peter and Saint Paul, easily recognisable by their respective attributes: the keys in the hand of Peter and the sword held by Paul. Likewise, at the main entrance to the Basilica of Saint Paul Outside the Walls, there are depictions of scenes from the life and the martyrdom of these two pillars of the Church.
Christian tradition has always considered Saint Peter and Saint Paul to be inseparable: indeed, together, they represent the whole Gospel of Christ.
In Rome, their bond as brothers in the faith came to acquire a particular significance. Indeed, the Christian community of this City considered them a kind of counterbalance to the mythical Romulus and Remus, the two brothers held to be the founders of Rome.
A further parallel comes to mind, still on the theme of brothers: whereas the first biblical pair of brothers demonstrate the effects of sin, as Cain kills Abel, yet Peter and Paul, much as they differ from one another in human terms and notwithstanding the conflicts that arose in their relationship, illustrate a new way of being brothers, lived according to the Gospel, an authentic way made possible by the grace of Christ's Gospel working within them.
In a passage from Saint Matthew's Gospel, Peter makes his own confession of faith in Jesus, acknowledging him as Messiah and Son of God. He does so in the name of the other Apostles too. In reply, the Lord reveals to him the mission that he intends to assign to him, that of being the "rock", the visible foundation on which the entire spiritual edifice of the Church is built (cf. Mt 16:16-19).
But in what sense can Peter be described as the rock? How is he to exercise this prerogative, which naturally he did not receive for his own sake? The account given by the evangelist Matthew tells us first of all that the acknowledgment of Jesus' identity made by Simon in the name of the Twelve did not come "through flesh and blood", that is, through his human capacities, but through a particular revelation from God the Father.
By contrast, immediately afterwards, as Jesus foretells his passion, death and resurrection, Simon Peter reacts on the basis of "flesh and blood": he "began to rebuke him, saying, this shall never happen to you" (16:22). And Jesus in turn replied: "Get behind me, Satan! You are a hindrance to me ..." (16:23).
The disciple who, through God's gift, was able to become a solid rock, here shows himself for what he is in his human weakness: a stone along the path, a stone on which men can stumble – in Greek, skandalon.
Here we see the tension that exists between the gift that comes from the Lord and human capacities and in this scene between Jesus and Simon Peter we see anticipated in some sense the drama of the history of the papacy itself, characterised by the joint presence of these two elements: on the one hand, because of the light and the strength that come from on high, the papacy constitutes the foundation of the Church during its pilgrimage through history; on the other hand, across the centuries, human weakness is also evident, which can only be transformed through openness to God's action.
In the Gospel account there also emerges powerfully the clear promise made by Jesus that "the gates of the underworld", that is, the forces of evil, will not prevail, non praevalebunt. One is reminded of the account of the call of the prophet Jeremiah, to whom the Lord said, when entrusting him with his mission: "Behold, I make you this day a fortified city, an iron pillar, and bronze walls, against the whole land, against the kings of Judah, its princes, its priests, and the people of the land. They will fight against you but they shall not prevail against you, for I am with you, says the Lord, to deliver you!" (Jer 1:18-19).
The symbol of the keys, referred to in Matthew, echoes the oracle of the prophet Isaiah concerning the steward Eliakim, of whom it was said: "And I will place on his shoulder the key of the house of David he shall open, and none shall shut and he shall shut, and none shall open" (Is 22:22).
The key represents authority over the house of David. And in the Gospel there is another saying of Jesus addressed to the scribes and the Pharisees, whom the Lord reproaches for shutting off the kingdom of heaven from people (cf. Mt 23:13). This saying also helps us to understand the promise made to Peter: to him, inasmuch as he is the faithful steward of Christ's message, it belongs to open the gate of the Kingdom of Heaven, and to judge whether to admit or to refuse (cf. Rev 3:7).
Hence the two images – that of the keys and that of binding and loosing – express similar meanings which reinforce one another.
As I mentioned at the beginning, the iconographic tradition represents Saint Paul with a sword, and we know that this was the instrument with which he was killed. Yet as we read the writings of the Apostle of the Gentiles, we discover that the image of the sword refers to his entire mission of evangelisation. For example, when he felt death approaching, he wrote to Timothy: "I have fought the good fight" (2 Tim 4:7).
This was certainly not the battle of a military commander but that of a herald of the Word of God, faithful to Christ and to his Church, to which he gave himself completely. And that is why the Lord gave him the crown of glory and placed him, together with Peter, as a pillar in the spiritual edifice of the Church.