CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 332–336

332 Angels have been present since creation and throughout the history of salvation, announcing this salvation from afar or near and serving the accomplishment of the divine plan: they closed the earthly paradise; protected Lot; saved Hagar and her child; stayed Abraham's hand; communicated the law by their ministry; led the People of God; announced births and callings; and assisted the prophets, just to cite a few examples. Finally, the angel Gabriel announced the birth of the Precursor and that of Jesus himself.
333 From the Incarnation to the Ascension, the life of the Word incarnate is surrounded by the adoration and service of angels. When God "brings the firstborn into the world, he says: 'Let all God's angels worship him.'" Their song of praise at the birth of Christ has not ceased resounding in the Church's praise: "Glory to God in the highest!" They protect Jesus in his infancy, serve him in the desert, strengthen him in his agony in the garden, when he could have been saved by them from the hands of his enemies as Israel had been. Again, it is the angels who "evangelize" by proclaiming the Good News of Christ's Incarnation and Resurrection. They will be present at Christ's return, which they will announce, to serve at his judgment.
334 In the meantime, the whole life of the Church benefits from the mysterious and powerful help of angels.
335 In her liturgy, the Church joins with the angels to adore the thrice-holy God. She invokes their assistance (in the funeral liturgy's In Paradisum deducant te angeli. . .["May the angels lead you into Paradise. . ."]). Moreover, in the "Cherubic Hymn" of the Byzantine Liturgy, she celebrates the memory of certain angels more particularly (St. Michael, St. Gabriel, St. Raphael, and the guardian angels).
336 From its beginning until death, human life is surrounded by their watchful care and intercession. "Beside each believer stands an angel as protector and shepherd leading him to life." Already here on earth the Christian life shares by faith in the blessed company of angels and men united in God.