Catechism of the Catholic Church

"The wonderful works of God among the people of the Old Testament were but a prelude to the work of Christ the Lord in redeeming mankind and giving perfect glory to God. He accomplished this work principally by the Paschal mystery of his blessed Passion, Resurrection from the dead, and glorious Ascension, whereby dying he destroyed our death, rising he restored our life.' For it was from the side of Christ as he slept the sleep of death upon the cross that there came forth the wondrous sacrament of the whole Church.'" For this reason, the Church celebrates in the liturgy above all the Paschal mystery by which Christ accomplished the work of our salvation.