Catechism of the Catholic Church §1155 — excerpt
The liturgical word and action are inseparable both insofar as they are signs and instruction and insofar as they accomplish what they signify. When the Holy Spirit awakens faith, he not only gives an understanding of the Word of God, but through the sacraments also makes present the "wonders" of God which it proclaims.
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.