Here are the posts summarizing the Catechism’s second pillar, “The Celebration of the Christian Mystery,” on the liturgy and the sacraments.
As a preamble, Pope Francis’ encyclical Lumen Fidei (“Light of Faith”) reminds us that the sacraments are encounters with God:
For transmitting a purely doctrinal content, an idea might suffice, or perhaps a book, or the repetition of a spoken message. But what is communicated in the Church, what is handed down in her living Tradition, is the new light born of an encounter with the true God, a light which touches us at the core of our being and engages our minds, wills and emotions, opening us to relationships lived in communion.
There is a special means for passing down this fullness, a means capable of engaging the entire person, body and spirit, interior life and relationships with others. It is the sacraments, celebrated in the Church’s liturgy. The sacraments communicate an incarnate memory, linked to the times and places of our lives, linked to all our senses; in them the whole person is engaged as a member of a living subject and part of a network of communitarian relationships. While the sacraments are indeed sacraments of faith, it can also be said that faith itself possesses a sacramental structure.
The awakening of faith is linked to the dawning of a new sacramental sense in our lives as human beings and as Christians, in which visible and material realities are seen to point beyond themselves to the mystery of the eternal.
Lumen Fidei, 40