Catechism of the Catholic Church §333 — excerpt
From the Incarnation to the Ascension, the life of the Word incarnate is surrounded by the adoration and service of angels. '" Their song of praise at the birth of Christ has not ceased resounding in the Church's praise: "Glory to God in the highest!"
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: Macc 10:29-30