The Christmas Mystery: The Incarnation
The mystery of the Incarnation is one of the three great mysteries of our religion with the mystery of the Holy Trinity, the mystery of one God in three persons, and the mystery of Redemption, the mystery of the ransoming of the human race through the sacrifice of the holy humanity of Christ.
Here is how Dom Guéranger presents the Christmas Mystery, the Incarnation, in his Liturgical Year:
Everything is mystery in this holy season. The Word of God, whose generation is before the day star, is born in time—a Child is God—a Virgin becomes a Mother, and remains a Virgin—things divine are commingled with those that are human—and the sublime, the ineffable antithesis, expressed by the Beloved Disciple in those words of his Gospel: The Word was made flesh, is repeated in a thousand different ways in all the prayers of the Church; —and rightly, for it admirably embodies the whole of the great portent which unites in one Person the nature of Man and the nature of God.
The splendor of this Mystery dazzles the understanding, but it inundates the heart with joy. It is the consummation of the designs of God in time. It is the endless subject of admiration and wonder to the Angels and Saints, nay, it is the source and cause of their beatitude.
(Source : Dom Guéranger – FSSPX.Actualités)