Catechism of the Catholic Church §96 — excerpt
What Christ entrusted to the apostles, they in turn handed on by their preaching and writing, under the inspiration of the Holy Spirit, to all generations, until Christ returns in glory.
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.