Roman Catechism 15.12

Chapter 15 — Part II: The Sacraments — Introduction on the Sacraments in General

Section 12. Nor is it unimportant that the faithful should know that the Sacraments are signs. This knowledge will lead them more readily to believe that what the Sacraments signify, contain and effect is holy and august; and recognising their sanctity they will be more disposed to venerate and adore the beneficence of God displayed towards us.