Catechism of the Catholic Church §521 — excerpt
Christ enables us to live in him all that he himself lived, and he lives it in us. "By his Incarnation, he, the Son of God, has in a certain way united himself with each man."
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: GS 22 # 2 · St. John Eudes: LH, week 33, Friday, OR