St Luke places the account of the event of Pentecost in the second chapter of the Acts of the Apostles. The chapter is introduced by the words: 'When the day of Pentecost had come, they were all together in one place' (Acts 2: 1). These words refer to the previous setting in which Luke described the small company of disciples that had gathered perseveringly in Jerusalem after Jesus' Ascension into Heaven (cf. Acts 1:12-14).
It is a description rich in detail: the place 'where they were staying' - the Cenacle - was an 'Upper Room'; the 11 Apostles are listed by name and the first three are Peter, John and James, the 'pillars' of the community; mentioned with them are 'the women' and 'Mary the Mother of Jesus', and 'his brethren', already an integral part of this new family, no longer based on blood ties but on faith in Christ.
This community was gathered in the same place, the Upper Room, on the morning of the Jewish Feast of Pentecost, the feast of the Covenant which commemorated the Sinai event, when God, through Moses, proposed that Israel be his own possession among all peoples to be a sign of his holiness (cf. Ex 19).
Wind and fire
According to the Book of Exodus, that ancient pact was accompanied by a terrifying manifestation of power by the Lord when we read: 'Mount Sinai was wrapped in smoke, because the Lord descended upon it in fire; and the smoke of it went up like the smoke of a kiln, and the whole mountain quaked greatly' (Ex 19:18).
We find the elements of wind and fire in the Pentecost of the New Testament, but untainted by fear. The fire specifically took the form of tongues of flame which settled on each one of the disciples who 'were all filled with the Holy Spirit' and through the effect of this outpouring 'began to speak in other tongues' (Acts 2:4).
It was a true and proper 'baptism' of fire of the community, a sort of new creation. At Pentecost, the Church was not established by human will but by the power of God's Spirit. And it is immediately clear how this Spirit gives life to a community which is at the same time one and universal, thereby overcoming the curse of Babel (cf. Gn 11:7-9).
Indeed, it is only the Holy Spirit who creates unity in love and in the reciprocal acceptance of diversity which can free humanity from the constant temptation to acquire earthly power that seeks to dominate and standardise all things.
'Societas Spiritus', a society of the Spirit, is what St Augustine calls the Church in one of his homilies (71, 19, 32: PL 38, 462). However, prior to him St Irenaeus had already formulated a truth which I would like to recall here: 'Where the Church is, there also is God's Spirit; where God's Spirit is, there is the Church and every grace; and the Spirit is the truth; to distance oneself from the Church is to reject the Spirit', and thus 'exclude oneself from life' (Adversus Haereses, III, 24, 1).
Beginning with the event of Pentecost this union between Christ's Spirit and his Mystical Body, in other words the Church, was fully manifest. I would like to reflect on a particular aspect of the Holy Spirit's action, that is, the manner in which multiplicity and unity are interwoven.
In the event of Pentecost it becomes clear that many languages and different cultures are part of the Church; in faith they can be understood and make one another fruitful. St Luke aims unambiguously to convey a fundamental idea, which is, that the very act of the Church's birth is already 'catholic' or universal.
From the outset the Church speaks in all languages, because the Gospel entrusted to her is destined for all peoples, according to the will and mandate of the Risen Christ (cf. Mt 28:19). The Church which is born at Pentecost is not primarily a particular community - the Church of Jerusalem - but the universal Church, which speaks the languages of all peoples. From her other communities were to be born, in every part of the world, particular Churches which are all and always actualisations of the one and only Church of Christ.
The Catholic Church is therefore not a federation of Churches but a single reality: the universal Church has ontological priority. A community which was not catholic in this sense would not even be a Church.
Journey to Rome
In this regard, it is necessary to add another aspect: that of the theological vision of the Acts of the Apostles concerning the journey to Rome of the Church of Jerusalem.
Among the peoples represented in Jerusalem on the Day of Pentecost, Luke also mentions 'visitors from Rome' (Acts 2:10). At that time Rome was still distant, 'foreign' to the newborn Church: it was a symbol of the pagan world in general. But the power of the Holy Spirit was to guide the footsteps of the witnesses 'to the end of the earth' (Acts 1:8), even to Rome.
The Acts of the Apostles ends precisely when St Paul, through a providential plan, reaches the capital of the Empire and proclaims the Gospel there (cf. Acts 28:30-31).
Thus the journey of the Word of God which began in Jerusalem reached its destination, because Rome represents the entire world and therefore embodies Luke's idea of catholicity. The universal Church is brought into being, the Catholic Church, which is the extension of the Chosen People and makes its history and mission her own.
This is the shortened text of Benedict XVI's homily at the Mass in St Peter's Basilica for the Feast of Pentecost, 11 May 2008.