Catechism of the Catholic Church

In the sacramental economy the Holy Spirit fulfills what was prefigured in the Old Covenant. Since Christ's Church was "prepared in marvellous fashion in the history of the people of Israel and in the Old Covenant," the Church's liturgy has retained certain elements of the worship of the Old Covenant as integral and irreplaceable, adopting them as her own: (762, 121, 2585, 1081) - notably, reading the Old Testament; - praying the Psalms; - above all, recalling the saving events and significant realities which have found their fulfillment in the mystery of Christ (promise and covenant, Exodus and Passover, kingdom and temple, exile and return).