Luke concludes "the Gospel of Jesus' infancy" with two texts which include the whole range of Jesus' childhood and youth. Between these two texts is the account of the episode of the losing and finding of Jesus in the Temple during the Holy Family's pilgrimage. Neither of these passages explicitly mentions the Holy Spirit. But anyone who followed the evangelist's narrative of the infancy events and continues to read the next chapter concerning John the Baptist's preaching and the baptism of Jesus in the Jordan, where the unseen protagonist is the Holy Spirit (cf. Lk 3:16, 22), perceives the continuity of Luke's idea and narrative. It includes Jesus' childhood years within the action of the Holy Spirit. Those years were lived in the hidden mystery of Nazareth. The theology of grace and of the gifts of the Holy Spirit helps us to understand the depths of this mystery which will always constitute the most intimate dimension of Jesus' humanity.
After having informed us that, having fulfilled the ritual of the presentation in the Temple, "they returned to Galilee, to their own town of Nazareth," the evangelist adds: "The child grew and became strong, filled with wisdom; and the favor of God was upon him" (Lk 2:40). And again, at the end of the account of the pilgrimage to the Temple and the return to Nazareth, he notes: "And Jesus advanced in wisdom and favor before God and man" (Lk 2:52). From these texts we see that there was a real human development in Jesus, eternal Word of the Father who assumed human nature through his conception and birth of Mary. Infancy, childhood, adolescence and youth are the periods of his physical growth ("in age"), as is true of all those "born of woman," among whom he is rightly numbered, as St. Paul remarks (cf. Gal 4:4).
According to Luke's text, there was also a spiritual growth in Jesus. As a doctor who was attuned to the whole person, Luke took pains to note the total reality of the human facts, including the development of the child, in Jesus' case as well as in that of John the Baptist. Luke wrote about John: "the child grew and became strong in spirit" (Lk 1:80). He more specifically says of Jesus that "the child grew and became strong, filled with wisdom"; "he advanced in wisdom...and favor before God and man"; and again, "the favor of God was upon him" (Lk 2:40, 52).
In the evangelist's terminology, this "being upon" a person chosen by God for a mission is attributed to the Holy Spirit, as in the case of Mary (cf. Lk 1:35) and Simeon (cf. Lk 2:26). This evokes the transcendence, lordship and the intimate action of the one we proclaim as Dominum et vivificantem (the Lord and giver of life). The grace which, again according to Luke, was "upon" Jesus and in which he "grew," seems to indicate the mysterious presence and action of the Holy Spirit in which, according to the Baptist's proclamation reported by the four Gospels, Jesus would be baptized (cf. Mt 3:11; Mk 1:8; Lk 3:16; Jn 1:33).
The patristic and theological tradition helps us to interpret and explain Luke's text about Jesus' growth "in wisdom and favor" in relation to the Holy Spirit. St. Thomas, speaking about grace, repeatedly calls it gratia Spiritus Sancti (cf. Summa Theol., I-II, q. 106, a. 1), a free gift which expresses and concretizes God's favor toward the creature eternally loved by the Father (cf. I, q. 37, a. 2; q. 110, a. 1). Speaking of the cause of grace, he expressly says that "the principal cause is the Holy Spirit" (I-II, q. 112, a. 1, ad 1, 2).
It is a question of justifying and sanctifying grace which reinstates the person in God's friendship, in the kingdom of heaven (cf. I-II, q. 111, a. 1). "It is according to this grace that we understand the Holy Spirit's mission and his indwelling in the human person" (I, q. 43, a. 3). The Holy Spirit instilled the fullness of grace in Christ, for the personal union of the human nature with the Word of God, for the extreme nobility of his soul and for his sanctifying and salvific mission for the whole human race. St. Thomas affirms this on the basis of Isaiah's messianic text: "The Spirit of the Lord will rest upon him" (Is 11:2): "The Spirit which is in the person by means of habitual (or sanctifying) grace" (III, q. 7, a. 1, sed contra); and on the basis of the other text from John: "And we saw his glory, the glory as of the Father's only Son, full of grace and truth" (Jn 1:14) (III, q. 7, aa. 9-10). However, the fullness of grace in Jesus was in proportion to his age; there was always fullness, but a fullness which increased as he grew in age.
The same can be said of the wisdom which Christ had from the beginning in the fullness proper to the period of childhood. As he advanced in age, this fullness grew in him to a proportionate degree. It was not merely a matter of human knowledge and wisdom about divine things, which God infused into Christ through the communication of the Word subsisting in his humanity. Also, and most of all, we are dealing with wisdom as a gift of the Holy Spirit: the greatest of gifts, which is "the perfection of the faculties of the soul, in order to dispose them to the movement of the Holy Spirit. Now, we know very well from the Gospel that Christ's soul was moved most perfectly by the Holy Spirit. Luke tells us that 'Jesus, filled with the Holy Spirit, returned from the Jordan and was led by the Spirit into the desert' (Lk 4:1). Therefore, the gifts were in Christ in a most exalted manner" (III, q. 7, a. 5). Wisdom had primacy among these gifts.
We would like to continue talking about the marvelous chapters of St. Thomas, as well as of other theologians who studied the sublime spiritual greatness of Jesus' soul, where the Holy Spirit dwelt and worked in a perfect manner from infancy and throughout the entire time of his development. Here we can only indicate the wonderful ideal of holiness which Jesus offers everyone in his own concrete life, even children and young people. They are called to "grow in wisdom and favor before God and man," as Luke writes about the child from Nazareth. The same evangelist will later write in the Acts of the Apostles concerning the primitive Church which "was...built up and walked in the fear of the Lord, and with the consolation of the Holy Spirit" (Acts 9:31). It is a fascinating comparison, not only a linguistic repetition, but a conceptual one as well, of the mystery of grace which Luke saw present both in Christ and in the Church as a continuation of the life and mission of the Incarnate Word in history. The many children whom history and hagiography present to us as especially enlightened and moved by holy gifts are sharers and have leading roles in the Church's growth under the inspiration of the Holy Spirit. In our time also the Church is happy to salute them and present them as particularly shining images of the young Jesus, filled with the Holy Spirit.
[Entire text above taken from archive.org cache of Vatican.va website.]