If Pentecost is known, properly, as the “birthday” of the Christian Church, today is the Catholic Church’s “name day.” Unity in faith is one of the gifts of the Spirit, so Pentecost bespeaks a decidedly ecumenical flavor and agenda, but the Feast of Sts. Peter and Paul is a distinctly Roman day. This is why the Ecumenical Patriarch comes to Rome, or sends a legate, on this day as the Pope sends a legate to Istanbul on the Feast of St. Andrew.
The fact that the feast day is shared by the two greatest apostles tells us something about the nature of the Church. Peter is the rock, the foundation on which the Church is built. Paul is the great missionary, called to bring the Good News to the gentiles. The Catholic Church must always embody both vocations. It must be solid, rock solid, able to withstand the fads and threats that beset every age. It must also constantly be looking beyond itself, bringing the Gospels to the gentiles of our day. And not only to the gentiles, but the Church must bring the Gospel to those parts of our hearts and minds that remain hidden from the light of Christ.