Catechism of the Catholic Church §1129 — excerpt
The Church affirms that for believers the sacraments of the New Covenant are necessary for salvation. "Sacramental grace" is the grace of the Holy Spirit, given by Christ and proper to each sacrament.
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: Council of Trent (1547): DS 1604