If, in a certain sense, all of the Church's liturgical celebrations are great, the one of Pentecost is so in a singular manner, because, arriving at the 50th day, it marks the fulfillment of the Easter event, of the death and resurrection of the Lord Jesus, through the gift of the Risen Lord's Spirit. The Church has prepared us in recent days for Pentecost with her prayers, with the repeated and intense plea to God for a renewed outpouring of the Holy Spirit upon us.
The Church relived in this way the events of her origins, when the Apostles, gathered in the cenacle in Jerusalem "were perseverant and united in prayer together with some women and Mary, the mother of Jesus, and his brothers" (Acts 1:14). They were gathered in humble and confident expectation that the Father's promise communicated to them by Jesus would be fulfilled: "Before long you will be baptised in the Holy Spirit ... you will receive the power of the Holy Spirit, who will descend upon you" (Acts 1:5, 8).
The Holy Spirit is first of all the Creator Spirit and so Pentecost is the feast of creation. For us Christians the world is the fruit of an act of the love of God, who made all things and who rejoices in them because they are "good," "very good," as the account of creation states (cf. Genesis 1:1-31).
Thus God is not totally Other, unnamable and obscure. God reveals himself, he has a face, God is reason, God is will, God is love, God is beauty. The faith in the Creator Spirit is the faith in the Spirit whom the risen Christ bestowed upon the Apostles and bestows on each one of us; they are therefore inseparably joined.
The Holy Spirit is he who helps us recognise the Lord; he makes us pronounce the Church's profession of faith: "Jesus is Lord" (cf. 1 Corinthians 12:3b). "Lord" is the title given to God in the Old Testament, a title that in the reading of the Bible took the place of his unspeakable name. The Church's Creed is nothing more than the development of what is said with this simple affirmation: "Jesus is Lord."
The expression "Jesus is Lord" can be read in two senses. It means: Jesus is God, and at the same time: God is Jesus. The Holy Spirit illuminates this reciprocity: Jesus has divine dignity, and God has the human face of Jesus. God shows himself in Jesus and with this conveys to us the truth about ourselves.
The Evangelist John borrows an image from the account of creation, where it says that God breathed into man's nostrils a breath of life. The breath of God is life. Now the Lord breathes into our soul the new breath of life, the Holy Spirit, his most intimate essence, and in this way we are welcomed into the family of God.
With baptism and confirmation we are given this gift in a specific way, and with the sacraments of the Eucharist and penance it is continually repeated: the Lord breathes a breath of life into our soul. All of the sacraments, each in its proper way, communicate the divine life to man thanks to the Holy Spirit who works in them.
The Holy Spirit is both Creator and the Spirit of Jesus Christ, in a way however that the Father, Son and Holy Spirit are one single God. And we can add: The Holy Spirit animates the Church which does not derive from the human will, from reflection, from man's ability and from his capacity to organise, because if this were the case, she would have already become extinct long ago, just as every human thing passes. She is rather the Body of Christ animated by the Holy Spirit.
The images of wind and fire, used by St Luke to represent the coming of the Holy Spirit (cf. Acts 2:2-3), recall Sinai, where God was revealed to the people of Israel when he granted them his covenant. "Mount Sinai was covered in smoke because the Lord had descended upon it in fire" (cf. Exodus 19:18).
In fact Israel celebrated the 50th day after Passover, after the commemoration of the flight out of Egypt, as the feast of Sinai, the feast of the Covenant. When St Luke speaks of tongues of fire to represent the Holy Spirit, the ancient covenant, established on the basis of the Law received by Israel on Sinai, is recalled.
Thus, the event of Pentecost is represented as a new Sinai, as the gift of a new covenant in which the alliance with Israel is extended to all the peoples of the earth, in which all of the barriers of the old Law crumble and its holiest and immutable core appears, which is love, that precisely the Holy Spirit communicates and spreads, the love which embraces all things.
With this we are told something very important: that the Church is catholic from the very first moment, that her universality is not the fruit of the subsequent inclusion of diverse communities. From the first instant, in fact, the Holy Spirit created her as the Church of all peoples: she embraces the whole world, she transcends all frontiers of race, class, nation; she razes all the bastions and unites men in the profession of God one and triune.
From the very beginning the Church is one, catholic and apostolic: This is her true nature and as such she must be recognised. She is holy, not due to the capacity of her members, but because God himself, with his Spirit, always creates her, purifies her and sanctifies her.
This is the shortened text of Benedict XVI's homily given on 12 June 2011 when he celebrated Mass for the Feast of Pentecost in St Peter's Basilica.