Catechism of the Catholic Church §776 — excerpt
As sacrament, the Church is Christ's instrument. "She is taken up by him also as the instrument for the salvation of all," "the universal sacrament of salvation," by which Christ is "at once manifesting and actualizing the mystery of God's love for men."
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 9 # 2, 48 # 2 · GS 45 # 1 · Paul VI, June 22, 1973 · AG 7 # 2 · LG 17