1. The Acts of the Apostles show us the first Christian community united by a strong bond of fraternal communion: “All who believed were together and had all things in common; and they sold their possessions and goods and distributed them to all, as any had need” (Acts 2:44-45). There is no doubt that the Holy Spirit is at the root of this demonstration of love. His outpouring at Pentecost lays the foundations of the new Jerusalem, the city built on love, quite the opposite of the ancient Babel. According to the text of Genesis 11, the builders of Babel had decided to build a city with a great tower whose top would reach the heavens. The sacred author sees in this project a foolish pride which flows into division, discord and lack of communication. On the day of Pentecost, on the other hand, Jesus’ disciples do not want to climb arrogantly to the heavens but are humbly open to the gift that comes down from above. While in Babel the same language is spoken by all but they end up not understanding each other, on the day of Pentecost different languages are spoken, yet they are very clearly understood. This is a miracle of the Holy Spirit.

2. The Holy Spirit’s proper and specific action already within the Trinity is communion. “It can be said that in the Holy Spirit the intimate life of the Triune God becomes totally gift, an exchange of mutual love between the divine Persons, and that through the Holy Spirit God exists in the mode of gift. It is the Holy Spirit who is the personal expression of this self-giving, of this being-love” (Dominum et Vivificantem, n. 10). The third Person — we read in St Augustine — is “the supreme love that unites both the Persons” (De Trin., n. 7, 3, 6). Indeed the Father begets the Son by loving him; the Son is begotten by the Father, letting himself be loved and receiving from him the capacity to love; the Holy Spirit is love given in total gratuitousness by the Father, received with full gratitude by the Son, and returned by him to the Father. The Spirit is also the love and the personal gift which contains every created gift: life, grace and glory. The mystery of this communion shines forth in the Church, the Mystical Body of Christ, enlivened by the Holy Spirit. The Spirit himself makes us “one in Christ Jesus” (Gal 3:28) and thus integrates us within the same unity which binds the Son to the Father. We are left in wonder at this intense and intimate communion between God and us!

3. The Book of the Acts presents several symbolic situations which let us understand how the Spirit helps the Church to live communion in practice, enabling her to overcome the problems she will encounter from time to time. When persons who do not belong to the people of Israel enter the Christian community for the first time, a dramatic moment is experienced. The Church’s unity is put to the test. However at this moment the Spirit is to descend on the house of the first pagan to be converted, Cornelius, the centurion. He renews the miracle of Pentecost and works a sign favouring unity between the Jews and the Gentiles (cf. Acts 10-11). We can say that this is the direct manner of building communion: the Spirit intervenes with the full power of his grace and creates a new, utterly unforeseeable situation. But the Spirit frequently acts using human mediation. This is what happened — again, according to the narrative of the Acts — when a discussion arose within the community of Jerusalem about the daily distribution among the widows (cf. Acts 6:1ff.). Unity is then re-established thanks to the intervention of the Apostles who ask the community to elect seven men “full of the Spirit” (Acts 6:3; cf. 6:5) and they appoint this group of seven to serve tables. A critical moment is also experienced by the community of Antioch, which consisted of Christians who had formerly been Jews or pagans. Several Jewish-Christian converts insisted that the latter be circumcised and observe the law of Moses. Regarding this, St Luke writes “the Apostles and the elders were gathered together to consider this matter” (Acts 15:6), and after “there had been much debate”, they reached an agreement, formulated in the solemn words: “For it has seemed good to the Holy Spirit and to us ...” (Acts 15:28). Here it can clearly be seen how the Spirit acts through the mediation of the Church’s “ministers”. Between the Spirit’s two great paths: the direct one, more unpredictable and charismatic, and the mediated one, more permanent and institutional, there can be no real conflict. Both come from the same Spirit. In cases where human weakness might see causes for tension and conflict, it is necessary to abide by the discernment of authority, with the assistance of the Holy Spirit (cf. 1 Cor 14:37).

4. It is thanks to the “grace of the Holy Spirit” (Unitatis redintegratio, n. 4) that there is a desire for full unity among Christians. In this regard, it must never be forgotten that the Spirit is the first common gift to divided Christians. As “the principle of the Church’s unity” (ibid., n. 2), he urges us to rebuild it through conversion of heart, common prayer, mutual knowledge, ecumenical formation, theological dialogue, and co-operation in the various contexts of social service inspired by love. Christ gave his life so that all his disciples might be one (cf. Jn 17). The celebration of the Jubilee of the third millennium must represent a new phase in overcoming the divisions of the second millennium and, since unity is a gift of the Paraclete, it comforts us to recall that precisely on the doctrine of the Holy Spirit significant steps have been made towards unity among the various Churches, especially among the Catholic Church and the Orthodox Churches. In particular, on the specific problem of the Filioque concerning the relationship between the Holy Spirit and the Word who proceed from the Father, it is possible to maintain that the difference between the Latin and Eastern traditions does not affect the identity of the faith “in the reality of the same mystery confessed” but its expression, constituting a “legitimate complementarity” which does not jeopardize but indeed can enrich communion in the one faith (cf. Catechism of the Catholic Church, 248; Apostolic Letter Orientale lumen, 2 May 1995, n. 5; Note of the Pontifical Council for Promoting Christian Unity, 29 June 1995: The Greek and Latin Traditions Regarding the Procession of the Holy Spirit, L’Osservatore Romano English edition, 20 September 1995, p. 3).

5. Lastly the forthcoming Jubilee must also see fraternal love grow within the Catholic Church. That effective love which must prevail in every community “especially [for] those who are of the household of faith” (Gal 6:10), involves every member of the Church, every parish and diocesan community, every group, association and movement in a serious examination of conscience which will dispose hearts to accept the unifying action of the Holy Spirit. St Bernard’s words are still timely: “We all need one another: from others I receive the spiritual good which I do not have and do not possess.... And all our differences, which express the riches of God’s gifts, will hold good in the one house of the Father, which includes so many mansions. Now there is a division of graces: then there will be a distinction of glories. Unity, both here and there, consists in one and the same love” (Apology to William of St Thierry, IV, 8: PL 182, 9033-9034).