§1163

"Holy Mother Church believes that she should celebrate the saving work of her divine Spouse in a sacred commemoration on certain days throughout the course of the year. Once each week, on the day which she has called the Lord's Day, she keeps the memory of the Lord's resurrection. She also celebrates it once every year, together with his blessed Passion, at Easter, that most solemn of all feasts. In the course of the year, moreover, she unfolds the whole mystery of Christ .... Thus recalling the mysteries of the redemption, she opens up to the faithful the riches of her Lord's powers and merits, so that these are in some way made present in every age; the faithful lay hold of them and are filled with saving grace."