By the entrance to the Basilica of Santa Sabina in Rome, where I lived for nine years, the fifth century mosaics give equal dignity to Peter and Paul as cofounders of the diocese of Rome. They are identified respectively as the apostles to the Jews and to the Gentiles.
This was more than a territorial division of the mission. It implied different roles. Peter had been with the Lord since the beginning of his mission, 'during all the time that the Lord Jesus went in and out among us' (Acts 1.21). He had been at the centre of the Jewish community that Jesus gathered around himself. He was the guardian of the received tradition. Paul was the latecomer, was sent by Jesus to initiate a new moment in the evolution of the Church, the outreach to the Gentiles. This is symbolised by their basilicas, St Peter's in what is now the centre of Rome, and St Paul's outside the Walls, summoning us beyond the confines of any fortress that we may construct.
Inevitably there was friction between them which seems to have exploded at Antioch (Galatians 2.11). The Church evolves from the fruitful tension between fidelity to the tradition and the Spirit's ever-fresh impulse towards the new. In hindsight we can usually discern that what seemed revolutionary at the time was in fact a fruit of the tradition, and its faithful development, but in the heat of the moment this may be hard to see. This is the development of doctrine about which Cardinal Newman wrote.
In recent years, especially in the United States, there has often been bitter friction between so-called 'traditional' and 'progressive' Catholics. But though we may by temperament be more inclined to hang on to what we have received or to reach out the new, there cannot be an ultimate opposition between them, just as Peter and Paul may have been in tension in their lifetime, but both witnessed to their common faith by their martyrdom.
Of course, it is impossible to keep the perfect balance. Inevitably the Church has wobbled between tradition and innovation. It is interesting that it was St Peter's that was rebuilt as a triumphant symbol of the Church in the sixteenth century faced with the rise of Protestantism, whereas St Paul's without the walls was rather neglected until it was burnt down in 1823 and rebuilt. The Pope came to be seen more as the successor of St Peter, the rock upon which the Church was founded, the defender of the tradition. Pope Paul VI chose that name because he understood that the Papacy needed to recover Paul's outreach to those beyond the walls.
So on this feast day, let us refuse the divisions that are tearing the Body of Christ. Peter and Paul both died for the truth and the truth is beyond the grasp of any ideology. Both these saints, with their different missions, invite us to continue our pilgrimage towards it.