Catechism of the Catholic Church §816 — excerpt
"The sole Church of Christ [is that] which our Savior, after his Resurrection, entrusted to Peter's pastoral care, commissioning him and the other apostles to extend and rule it....
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 8 # 2 · UR 3 # 5