The Mass tells us that “the Word that came down from heaven during the night” of Christmas is “the Son of God who has come that we might participate of His heritage and receive the adoption of sons”.
Before His coming, man was as “a child who during his minority differeth nothing from a servant” (Epistle). On the contrary now that the New Law has emancipated him from the tutorship of the Old Law “he is no longer a servant but a son” (Epistle).
In revealing to us this supernatural filiation of Christ, which affects our souls more especially at this season of Christmas, the liturgy makes the Divinity under the aspect of Paternity resplendent in our eyes. Also, the worship of the sons of God is summed up in that word spoken with Jesus, “Father!” (Epistle).
The Gospel also discloses to us the glorious mission which the future has in store for the Child, the manifestation of which begins today in the Temple. “It is the King” (Gradual) “whose reign” (Alleluia) “will reach the very depths of the heart” (Gospel). For all it will be a touchstone, a stumbling block for those who will persecute Him (Communion), a cornerstone “for many in Israel” (Gospel).
The secret thoughts of each man in relation to Christ will be reveled on the last day, since He will search the reins of our hearts. Those who, either from pride or cowardice, have rejected the Son of God, will be in their turn rejected by Him, and those who have welcomed Him will participate in His glory, because it is to save His people that Jesus came. From the very commencement this divine Child was filled with the wisdom of His Father and his soul received the fullness of sanctifying grace.