M y fellow Christians, today is the birthday of this church, an occasion for celebration and rejoicing. We, however, ought to be the true and living temple of God. Nevertheless, Christians rightly commemorate this feast of the church, their mother, for they know that through her they were reborn in the spirit. At our first birth, we were vessels of God’s wrath; reborn, we became vessels of his mercy. Our first birth brought death to us, but our second restored us to life.
Indeed, before our baptism we were sanctuaries of the devil; but after our baptism we merited the privilege of being temples of Christ. And if we think more carefully about the meaning of our salvation, we shall realise that we are indeed living and true temples of God. God does not dwell only in things made by human hands, nor in homes of wood and stone, but rather he dwells principally in the soul made according to his own image and fashioned by his own hand. Therefore, the apostle Paul says: The temple of God is holy, and you are that temple.
When Christ came, he banished the devil from our hearts, in order to build in them a temple for himself. Let us therefore do what we can with his help, so that our evil deeds will not deface that temple. For whoever does evil, does injury to Christ. As I said earlier, before Christ redeemed us, we were the house of the devil, but afterward, we merited the privilege of being the house of God. God himself in his loving mercy saw fit to make of us his own home. My fellow Christians, do we wish to celebrate joyfully the birth of this temple? Then let us not destroy the living temples of God in ourselves by works of evil. I shall speak clearly, so that all can understand. Whenever we come to church, we must prepare our hearts to be as beautiful as we expect this church to be. Do you wish to find this basilica immaculately clean? Then do not soil your soul with the filth of sins. Do you wish this basilica to be full of light? God too wishes that your soul be not in darkness, but that the light of good works shine in us, so that he who dwells in the heavens will be glorified. Just as you enter this church building, so God wishes to enter into your soul, for he promised: I shall live in them, I shall walk through their hearts.
This excerpt from a sermon preached by St. Caesarius of Arles on the occasion of the dedication of a church (Sermo 229, 1-3: CCL 104, 905-908) is used in the Roman Office of Readings for the Feast of the Dedication of the Basilica of St. John Lateran, the mother church of Rome and therefore of all Catholic Churches, on November 9. The Lateran Basilica, erected by the Emperoro Constantinte, is called the mother church of all Christendom. The feast of its dedication was first observed only in Rome but was ultimately extended to the whole Latin Church as a sing of devotion to and unity with the Chair of Peter. The Basilica of St. John Lateran is the official cathedral of the Pope and was the place of residence of the Popes up until 1305.