1. “If Christ is the Head of the Church, the Holy Spirit is her soul”. So said my venerable Predecessor Leo XIII in the Encyclical Divinum illud munus (1897: DS 3328). After him, Pius XII explained that in the Mystical Body of Christ the Holy Spirit is “the principle of every vital and truly salvific action in each of the Body’s various members” (Encyclical Mystici Corporis, 1943: DS 3808).

Today we would like to reflect on the mystery of Christ’s Body which is the Church, inasmuch as she is enlivened and animated by the Holy Spirit.

After the Pentecost event, the group that gave rise to the Church profoundly changes: at first it was a closed, static group of “about a hundred and twenty” (Acts 1:15); later it was an open, dynamic group to which, after Peter’s address, “were added about three thousand souls” (Acts 2:41). The true newness did not consist so much in this numerical growth, however extraordinary, but in the presence of the Holy Spirit. A group of people is not enough to form a Christian community. The Holy Spirit brings the Church to birth. She appears — to use a happy phrase of the late Cardinal Congar — “entirely suspended from heaven” (La Pentecoste, Italian trans., Brescia, 1986, p. 60).

2. This birth in the Spirit, which occurred for the whole Church on Pentecost, is renewed for every believer at Baptism, when we are immersed “in one Spirit” to become members of “one body” (1 Cor 12:13). We read in St Irenaeus: “Just as flour cannot become one loaf without water, so we who are many cannot become one in Christ Jesus without the water that comes from heaven” (Adv. Haer., III, 17, 1). The water that comes from heaven and transforms the water of Baptism is the Holy Spirit.

St Augustine states: “What our spirit, i.e., our soul, is for our members, the Holy Spirit is for Christ’s members, for the Body of Christ which is the Church” (Serm. 267, 4).

In the Dogmatic Constitution on the Church, the Second Vatican Ecumenical Council returns to this image, develops it and explains it: Christ “has shared with us his Spirit who, being one and the same in head and members, gives life to, unifies and moves the whole body. Consequently, his work could be compared by the Fathers to the function that the principle of life, the soul, fulfils in the human body” (Lumen gentium, n. 7).

This relationship between the Spirit and the Church guides us in understanding her, without falling into the two opposite errors already pointed out by Mystici Corporis: ecclesiological naturalism, which is limited to the visible aspect and so regards the Church as a merely human institution; or the opposite error of ecclesiological mysticism, which emphasizes the Church’s unity with Christ to the point of considering Christ and the Church as a sort of physical person. These two errors are analogous — as Leo XIII had already stressed in the Encyclical Satis cognitum — to two Christological heresies: Nestorianism, which separated the two natures in Christ, and Monophysitism, which confused them. The Second Vatican Council offered us a synthesis which helps us grasp the true meaning of the Church’s mystical unity by presenting her as “one complex reality which comes together from a human and divine element” (Lumen gentium, n. 8).

3. The Holy Spirit’s presence in the Church enables her, despite being marked by the sin of her members, to be preserved from defect. Holiness not only replaces sin, but overcomes it. In this sense, too, we can say with St Paul that where sin abounds, grace even more abounds (cf. Rom 5:20).

The Holy Spirit dwells in the Church not as a guest who still remains an outsider, but as the soul that transforms the community into “God’s holy temple” (1 Cor 3:17; cf. 6:19; Eph 2:21) and makes it more and more like himself through his specific gift, which is love (cf. Rom 5:5; Gal 5:22). Love — the Second Vatican Council teaches in the Dogmatic Constitution on the Church — “governs, gives meaning to and perfects all the means of sanctification” (Lumen gentium, n. 42). Love is the “heart” of Christ’s Mystical Body, as we read in a beautiful autobiographical passage of St Thérèse of the Child Jesus: “I understood that if the Church had a body composed of different members, the most necessary and noble of all could not be lacking to it, and so I understood that the Church had a heart and that this heart was burning with Love. I understood that it was Love alone that made the Church’s members act, that if Love were ever extinguished, apostles would not proclaim the Gospel and martyrs would refuse to shed their blood.... I understood that Love included all vocations, that Love was everything, that it embraced all times and places ... in a word, that it was eternal!” (Autobiographical Manuscript B, 3vº).

4. The Spirit who dwells in the Church also abides in the heart of every member of the faithful: he is the dulcis hospes animae. Following a path of conversion and personal sanctification, then, means allowing ourselves to be “led” by the Spirit (cf. Rom 8:14), letting him act, pray and love in us. “Becoming holy” is possible if we allow ourselves to be made holy by him who is the Holy One, by docilely co-operating with his transforming action. For this reason, since the primary objective of the Jubilee is to strengthen the faith and witness of Christians, “it is necessary to inspire in all the faithful a true longing for holiness, a deep desire for conversion and personal renewal in a context of ever more intense prayer and of solidarity with one’s neighbour, especially the most needy” (Tertio millennio adveniente, n. 42).

We can think of the Holy Spirit as the soul of our soul, and thus the secret of our sanctification. Let us dwell in his powerful and discreet, intimate and transforming presence!

5. St Paul teaches us that the indwelling of the Holy Spirit within us is closely connected with Jesus’ Resurrection and is also the basis of our final resurrection: “If the Spirit of him who raised Jesus from the dead dwells in you, he who raised Christ Jesus from the dead will give life to your mortal bodies also through his Spirit who dwells in you” (Rom 8:11).

In eternal happiness we will live in the joyful fellowship that is now prefigured and anticipated by the Eucharist. Then the Spirit will bring to full maturity all the seeds of communion, love and brotherhood that have blossomed during our earthly pilgrimage. As St Gregory of Nyssa says, “surrounded by the unity of the Holy Spirit as the bond of peace, all will be one Body and one Spirit” (Hom. 15 in Cant.).

To the English-speaking pilgrims and visitors the Holy Father said:

I welcome the English-speaking pilgrims and visitors, especially those from Latvia, Japan, Scotland, Canada and the United States of America. Upon all of you I cordially invoke God’s blessings of joy and peace.