The Holy Spirit's role in the Incarnation

1. Jesus is linked with the Holy Spirit from the first moment of his existence in time, as the Nicene-Constantinopolitan Creed recalls: “Et incarnatus est de Spiritu Sancto ex Maria Virgine”. The Church’s faith in this mystery is based on the word of God: “The Holy Spirit”, the Angel Gabriel announces to Mary, “will come upon you and the power of the Most High will overshadow you; therefore the child to be born will be called holy, the Son of God” (Lk 1:35). And Joseph is told: “That which is conceived in her is of the Holy Spirit” (Mt 1:20).

The Holy Spirit's direct intervention in the Incarnation brings about the supreme grace, the “grace of union”, in which human nature is united to the Person of the Word. This union is the source of every other grace, as St Thomas explains (S. Th. III, q. 2, a. 10-12; q. 6, a. 6; q. 7, a. 13).

2. For a deeper understanding of the Holy Spirit’s role in the Incarnation event, it is important to return to what the word of God tells us.

St Luke says that the Holy Spirit will come upon Mary and overshadow her as power from on high. From the Old Testament, we know that every time God decides to bring forth life, he acts through the “power” of his creative breath: “By the word of the Lord the heavens were made, and all their host by the breath of his mouth” (Ps 33 [32]:6). This is true for every living being, to the point that if God “should take back his spirit to himself, and gather to himself his breath, all flesh [that is, every human being] would perish together, and man would return to dust” (Jb 34:14-15). God has his Spirit intervene especially at the moments when Israel feels powerless to raise itself by its own strength alone. The prophet Ezekiel suggests this in his dramatic vision of the immense valley filled with skeletons: “The breath came into them, and they lived, and stood upon their feet” (Ez 37:10).

The virginal conception of Jesus is “the greatest work accomplished by the Holy Spirit in the history of creation and salvation” (Dominum et Vivificantem, n. 50). In this event of grace, a virgin is made fruitful; a woman, redeemed since her conception, conceives the Redeemer. Thus a new creation is prepared, and the new and everlasting Covenant initiated: a man who is the Son of God begins to live. Never before this event had it been said that the Holy Spirit descended directly upon a woman to make her a mother. Whenever miraculous births occurred in Israel’s history, wherever they are mentioned, the divine intervention is related to the newborn child, not the mother.

3. If we ask ourselves what the Holy Spirit’s purpose was in bringing about the Incarnation event, the word of God gives us a succinct reply in the Second Letter of Peter, telling us that it happened so that we might become “partakers of the divine nature” (2 Pt 1:4). “In fact”, St Irenaeus of Lyons explains, “this is the reason why the Word became flesh and the Son of God became the Son of Man: so that man, by entering into communion with the Word and thus receiving divine shonship, might become a son of God” (Adv. Haer. III, 19, 1). St Athanasius adopts the same line: “When the Word came upon the Blessed Virgin Mary, the Spirit entered her together with the Word; in the Spirit the Word formed a body for himself and adapted it to himself, desiring to unite all creation through himself and lead it to the Father” (Ad Serap. 1, 31). These assertions are repeated by St Thomas: “The Only-begotten Son of God, wanting us to be partakers of his divinity, assumed our human nature so that, having become man, he might make men gods” (Opusc. 57 in festo Corp. Christi, 1), that is, partakers through grace of the divine nature.

The mystery of the Incarnation reveals God’s astonishing love, whose highest personification is the Holy Spirit, since he is the Love of God in person, the Person-Love: “In this the love of God was made manifest among us, that God sent his only Son into the world, so that we might live through him” (1 Jn 4:9). The glory of God is revealed in the Incarnation more than in any other work.

Quite rightly we sing in the Gloria in excelsis: “We praise you, we bless you ... we give you thanks for your great glory”. These statements can be applied in a special way to the action of the Holy Spirit who, in the First Letter of Peter, is called “the spirit of glory” (1 Pt 4:14). This is a glory which is pure gratuitousness: it does not consist of taking or receiving, but only of giving. In giving us his Spirit, who is the source of life, the Father manifests his glory, making it visible in our lives. In this regard St Irenaeus says that “the glory of God is the living man” (Adv. Haer. IV, 20, 7).

4. If now we try to look more closely at what the Incarnation event reveals to us of the mystery of the Spirit, we can say that this event shows us primarily that he is the gracious power of God who brings forth life.

The power that “overshadows” Mary recalls the cloud of the Lord which covered the tent in the desert (cf. Ex 40:34) or filled the temple (cf. 1 Kgs 8:10). Thus it is the friendly presence, the saving closeness of God who comes to make a covenant of love with his children. It is power in the service of love, which is exercised under the sign of humility: not only does it inspire the humility of Mary, the handmaid of the Lord, but is almost hidden behind her, to the point that no one in Nazareth can foresee that what “is conceived in her is of the Holy Spirit” (Mt 1:20). St Ignatius of Antioch marvellously describes this paradoxical mystery: “Mary’s virginity and her birth were hidden from the prince of this world, as was the death of the Lord. These are the three resounding mysteries that were accomplished in the quiet stillness of God” (Ad Eph., 19, 1).

5. The mystery of the Incarnation, seen from the perspective of the Holy Spirit who brought it about, also sheds light on the mystery of man.

If in fact the Spirit works in a unique way in the mystery of the Incarnation, he is also present at the origin of every human being. Our being is a “received being”, a reality thought of, loved and given. Evolution does not suffice to explain the origin of the human race, just as the biological causality of the parents alone cannot explain a baby’s birth. Even in the transcendence of his action, God is ever respectful of “secondary causes” and creates the spiritual soul of a new human being by communicating the breath of life to him (cf. Gn 2:7) through his Spirit who is “the giver of life”. Thus every child should be seen and accepted as a gift of the Holy Spirit.

The chastity of celibates and virgins is a unique reflection of that love “poured into our hearts through the Holy Spirit” (Rom 5:5). The Spirit, who gave the Virgin Mary a share in the divine fruitfulness, also ensures that those who have chosen virginity for the kingdom of heaven will have numerous descendants in the spiritual family formed of all those who “were born, not of blood nor of the will of the flesh nor of the will of man, but of God” (Jn 1:13).

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

I warmly welcome the group from the NATO Defense College: I encourage you always to see your professional duties as an effective service of the cause of peace. Upon all the English-speaking pilgrims and visitors, especially those from England, Scotland, Canada and the United States of America, I invoke the abundant blessings of almighty God.