Catechism of the Catholic Church §1190 — excerpt
The Liturgy of the Word is an integral part of the celebration. the meaning of the celebration is expressed by the Word of God which is proclaimed and by the response of faith to 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.