The Solemnity of the Annunciation of the Lord celebrates the visit of the Archangel Gabriel to the Virgin Mary to announce to her that she will be the mother of the Savior.
During this feast, we Catholics wear liturgical garments of white and recite the Gloria at the beginning of Mass, both symbols of the joy that accompanies the Incarnation – Christ becoming human and choosing to be born of one of us.
Even during the solemn penitential time of Lent, the Church acknowledges the arrival of the Savior with hope and joy. For Catholics, the theological significance of the Annunciation is that it marks the beginning of the fulfillment of God's promises and preparations.
"Mary's consent to the angel's announcement is the beginning of the Incarnation of Christ; God coming into the world as a full human born as we are, with a human mother full of grace."