The Holy Father gave this catechesis at the General Audience on 28 Nov.:

1. Today we being a new series of catecheses in the cycle on the Holy Spirit in which I have sought to draw the attention of my listeners both near and far to the basic Christian truths about the Holy Spirit. We have seen that the New Testament, led up to by the Old, permits us to come to know the Spirit as a Person of the Blessed Trinity. It is a fascinating truth, because of both its inner meaning and its influence on our lives. We can even say that it is a truth-for-living, just as is all the revelation, which is summed up in the Creed. In a special way the Holy Spirit has been revealed to us and given to us so that He may be life's light and guide for us, for the whole Church and for all people called to know Him.

2. We are speaking especially about the spirit as life-giving principle of the Church. We saw earlier during the Christological catechetical series that from the start of His messianic mission Jesus gathered around Himself disciples; from among them He chose the Twelve, called Apostles, and from among them he assigned the prime role as His witness and representative to Peter (cf. Mt 16:18). When on the eve of His sacrifice on the Cross, He instituted the Eucharist, He commanded and empowered these Apostles to celebrate it in His memory (cf. Lk 22:19; I Cor 11: 24-25). After the Resurrection He conferred on them the power to forgive sins (cf. Jn 20:22-23) and gave them the command to evangelize the whole world (cf. Mk 16:15).

We can say that all of that is tied to the announcement and the promise of the Holy Spirit's coming which occurred on the day of Pentecost, as the Acts of the Apostles relates (2:1-4).

3. The Second Vatican Council gives us several significant texts on the decisive importance of the day of Pentecost, which is often called the birthday of the Church in the world's eyes. In fact, we read in the Constitution Dei Verbum that "by sending the Holy Spirit of truth, Christ revealed to us that God was with us to deliver us from the darkness of sin and death and to raise us up to eternal life" (n.4). Therefore there is a close link between Jesus Christ and the Holy Spirit in the work of salvation.

In its turn the Constitution Lumen Gentium on the Church says: "He is the Spirit of life, the fountain of water springing up to eternal life (Jn 4:47; 7:38-39). To people dead in sin, the Father gives life through Him until the day when, in Christ, He raises to life their mortal bodies" (n.4). Therefore, through the power and action of the Spirit through whom Christ was raised up, those who are incorporated into Christ will be raised. This is St Paul's teaching, which the Council adopted (cf. Rm 8:10-11).

The Council adds that in descending upon the Apostles, the Holy Spirit gave birth to the Church (cf. Lumen Gentium, 19), which is described in the New Testament and especially in St Paul as the Body of Christ: "The Son of God ... in communicating His Spirit, mystically constituted as His Body (tamquam corpus suum mystice constituit) those brothers and sisters of His who are called together from every nation" (LG n.7).

Christian tradition, which employs the Pauline theme of Ecclesia Corpus Christi, whose life-giving principle, according to the Apostle, is the Holy Spirit, comes to the conclusion in a most beautiful phrase that the Holy Spirit is the Church's "soul". Here we need only quote St Augustine who in a speech states that "what our spirit, that is, our soul, is in relation to our other members, so the Holy Spirit is to the members of Christ, that is, the Body of Christ which is the Church" (Sermon 269,2; PL 38,1232). Very evocative also is a text of St Thomas Aquinas who, in speaking of Christ as head of the Body of the Church, compares the Holy Spirit to the heart, because "invisibly He gives life to and unifies the Church", just as the heart "carries out its inner influence within the human body" (III, q.8, a. l, ad 3).

The Holy Spirit as "soul of the Church" and "heart of the Church": this is a beautiful aspect of Tradition, which we must delve into more deeply.

4. It is clear that, as theologians explain, the expression: "The Holy Spirit animates the Church" is understood as an analogy. He, in truth, is not the "substantial form" of the Church as the soul is for the body together with which it forms the one substance we call the human being. The Holy Spirit is the vital principle of the Church, intimate, yet transcendent. He is the Giver of life and unity to the Church, along the lines of the efficient cause, that is as the author and promoter of divine life in the Corpus Christi. The Council calls attention to this and states that "in order that we might be unceasingly renewed in Him (cf. Eph 4:23) He 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" (LG 7).

Following this analogy one could draw a comparison between the whole process of the formation of the Church, already within the sphere of the messianic activity of Christ on earth, and the creation of the human being according to the Book of Genesis, and especially the breathing in of the "breath of life" by which "man became a living being" (Gn 2:7). The term used in the Hebrew text is nefesh (to be animated by a life-giving breath); but in another passage in Genesis the vital breath of the living beings is called ruah, that is, "spirit" (Gn 6:17). According to this analogy the Holy Spirit can be considered to be the vital breath of the "new creation" which is realized in the Church.

5. The Council tells us in another place that "the Holy Spirit was sent on the day of Pentecost in order that He might continually sanctify the Church and that consequently those who believe might have access in one Spirit to the Father (cf. Eph 2:18)" (LG n.4). Holiness is the first and the basic form of life that the Holy Spirit, like the "life-giving soul", infuses into the Church—holiness after the model of Christ "whom the Father consecrated and sent into the world" (Jn 10:36). Holiness constitutes the Church's basic identity as the Body of Christ, given life and sharing in His Spirit. Holiness gives the Body spiritual health. Holiness also determines its spiritual beauty: a beauty which surpasses all natural or artistic beauty; a supernatural beauty in which the beauty of God Himself is reflected in a more essential and direct way than in any other created beauty, precisely because it is the Corpus Christi. In another catechesis we shall return to the theme of the Church's holiness.

6. The Holy Spirit is called the "Church's soul" also in the sense that He sheds divine light on all thought within the Church, and "guides to all truth", according to the announcement made by Christ in the Upper Room: "When the Spirit of truth comes, He will guide you to all truth. He will not speak on His own, but will speak only what He hears ..., what He will announce to you He will have from Me" (Jn 16:13, 15).

Therefore it is by the Holy Spirit's light that the Church comes to the announcement of the revealed truth, and a deepening of faith on all levels of the Corpus Christi is at work: among the Apostles, among their successors in the ministry, and regarding the "sense of faith" of all believers, among whom are the catechists, the theologians, and other Christian thinkers. All is and must be enlivened by the Spirit. 

7. The Holy Spirit is also the source of all dynamism in the Church, whether we are referring to the witness she must give to Christ before the world, or to the spread of the Gospel message. In Luke's Gospel when the Risen Christ tells the Apostles about the coming of the Holy Spirit, He stresses precisely this aspect: "I send down upon you the promise of My Father. Remain here in the city until you are clothed with power from on high" (Lk 24:49). The link between the Holy Spirit and power is still clearer in the parallel account in the Acts of the Apostles where Jesus says: "You will receive power when the Holy Spirit comes down upon you and you will be my witnesses ..." (Acts 1:8). In both the Gospel and in Acts the Greek word for power or strength is dynamis: "dynamism". This refers to a supernatural energy which on a person's part requires prayer most of all. This is a further teaching of the Second Vatican Council, according to which the Holy Spirit "dwells in the Church and in the faithful and in them prays and bears witness to their adoptive sonship" (LG n.4). In the same text, the Council cites St Paul (cf. Gal 4:6; Rom 8:15-16, 26); we want especially to mention the passage from the Letter to the Romans: "The Spirit aids us in our weakness for we do not know how to pray as we ought; but the Spirit Himself makes intercession for us with groanings that cannot be expressed in speech" (8:26).

8. To conclude all that we have said so far, let us reread another brief conciliar text, which says that the Holy Spirit "constantly renews the Church and leads her to perfect union with her Spouse. For the Spirit and the Bride both say to Jesus the Lord: 'Come' (Rev 22:7)". This text echoes St Irenaeus (Adv. Haereses, III, 14,1: PG, 7, 966 B), who communicates to us the certainty of faith of the earliest Fathers. It is the same certainty announced by St Paul when he said that the believers have been breed from slavery to the letter "to serve in the new spirit" (Rom 7:6). The whole Church is under this new spirit and discovers in the Holy Spirit the source of her continued renewal and her unity. This is due to the fact that the power of the Spirit who is life giving and unifying Love is stronger than all human weakness and sins.