17 When the Holy Family returns to Nazareth after Herod's death, there begins the long period of the hidden life. She "who believed that there would be a fulfillment of what was spoken to her from the Lord" (Lk. 1:45) lives the reality of these words day by day. And daily at her side is the Son to whom "she gave the name Jesus"; therefore in contact with him she certainly uses this name, a fact which would have surprised no one, since the name had long been in use in Israel. Nevertheless, Mary knows that he who bears the name Jesus has been called by the angel "the Son of the Most High" (cf. Lk. 1:32). Mary knows she has conceived and given birth to him "without having a husband," by the power of the Holy Spirit, by the power of the Most High who overshadowed her (cf. Lk. 1:35), just as at the time of Moses and the Patriarchs the cloud covered the presence of God (cf. Ex. 24:16; 40:34-35; I Kings 8:10-12). Therefore Mary knows that the Son to whom she gave birth in a virginal manner is precisely that "Holy One," the Son of God, of whom the angel spoke to her. During the years of Jesus' hidden life in the house at Nazareth, Mary's life too is "hid with Christ in God" (cf. Col. 3:3) through faith. For faith is contact with the mystery of God. Every day Mary is in constant contact with the ineffable mystery of God made man, a mystery that surpasses everything revealed in the Old Covenant. From the moment of the Annunciation, the mind of the Virgin-Mother has been initiated into the radical "newness" of God's self-revelation and has been made aware of the mystery. She is the first of those "little ones" of whom Jesus will say one day: "Father, ...you have hidden these things from the wise and understanding and revealed them to babes" (Mt. 11:25). For "no one knows the Son except the Father" (Mt. 11:27). If this is the case, how can Mary "know the Son"? Of course she does not know him as the Father does; and yet she is the first of those to whom the Father "has chosen to reveal him" (cf. Mt. 11:26-27; 1 Cor. 2:11). If though, from the moment of the Annunciation, the Son-whom only the Father knows completely, as the one who begets him in the eternal "today" (cf. Ps. 2:7) was revealed to Mary, she, his Mother, is in contact with the truth about her Son only in faith and through faith! She is therefore blessed, because "she has believed," and continues to believe day after day amidst all the trials and the adversities of Jesus' infancy and then during the years of the hidden life at Nazareth, where he "was obedient to them" (Lk. 2:51). He was obedient both to Mary and also to Joseph, since Joseph took the place of his father in people's eyes; for this reason, the Son of Mary was regarded by the people as "the carpenter's son" (Mt. 13:55). The Mother of that Son, therefore, mindful of what has been told her at the Annunciation and in subsequent events, bears within herself the radical "newness" of faith: the beginning of the New Covenant. This is the beginning of the Gospel, the joyful Good News. However, it is not difficult to see in that beginning a particular heaviness of heart, linked with a sort of night of faith"-to use the words of St. John of the Cross-a kind of "veil" through which one has to draw near to the Invisible One and to live in intimacy with the mystery. And this is the way that Mary, for many years, lived in intimacy with the mystery of her Son, and went forward in her "pilgrimage of faith," while Jesus "increased in wisdom...and in favor with God and man" (Lk. 2:52). God's predilection for him was manifested ever more clearly to people's eyes. The first human creature thus permitted to discover Christ was Mary, who lived with Joseph in the same house at Nazareth. However, when he had been found in the Temple, and his Mother asked him, "Son, why have you treated us so?" the twelve-year-old Jesus answered: "Did you not know that I must be in my Father's house?" And the Evangelist adds: "And they (Joseph and Mary) did not understand the saying which he spoke to them" (Lk. 2:48-50). Jesus was aware that "no one knows the Son except the Father" (cf. Mt. 11:27); thus even his Mother, to whom had been revealed most completely the mystery of his divine sonship, lived in intimacy with this mystery only through faith! Living side by side with her Son under the same roof, and faithfully persevering "in her union with her Son," she "advanced in her pilgrimage of faith," as the Council emphasizes. And so it was during Christ's public life too (cf. Mk. 3:21-35) that day by day there was fulfilled in her the blessing uttered by Elizabeth at the Visitation: "Blessed is she who believed."
Source: Redemptoris Mater (Vatican.va)