Catechism of the Catholic Church §959 — excerpt
In the one family of God. "For if we continue to love one another and to join in praising the Most Holy Trinity - all of us who are sons of God and form one family in Christ - we will be faithful to the deepest vocation of the Church."
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: LG 51