The Paschal mystery is one of the central concepts of Catholic faith relating to the history of salvation. According to the Compendium of the Catechism of the Catholic Church, "The Paschal Mystery of Jesus, which comprises his passion, death, resurrection, and glorification, stands at the center of the Christian faith because God's saving plan was accomplished once for all by the redemptive death of himself as Jesus Christ." The Catechism states that in the liturgy of the Church "it is principally his own Paschal mystery that Christ signifies and makes present." Catholic, Anglican and Orthodox Christian churches celebrate this mystery on Easter. It is recalled and celebrated also during every Eucharist, and especially on a Sunday, which according to Catholicism is the Pascha of the week. According to the Book of Exodus, God commanded Moses to tell the Israelites to mark a lamb's blood above their doors in order that the Angel of Death would pass over them. Paschal refers to the passage of God's destroying angel on the night of Passover. The angel "passed over" the houses of the Israelites but killed the firstborn child in the houses of the Egyptians. Catholicism says that a sacred mystery is a divine mystery which cannot be grasped by mere human reasoning and can only be revealed by God through grace. The first known use of the term Paschal mystery (literally Mystery of the Pascha) was found in the homily of Melito of Sardis On the Pascha written between A.D. 160 and 170: According to Raniero Cantalamessa OFMCap, patristic interpretation of the paschal mystery in its major facets and constituent dimensions may be summarized in four points: History. Historical events form the foundation for the Paschal mystery and are commemorated in the paschal liturgy of Easter Sacraments and mystagogy. Historical events of the death and resurrection of Christ are realized in the believer as passage from death to life. Primarily, it is achieved in baptism and the Eucharist, but the paschal solemnity of Easter taken as a whole is itself a sacrament, the paschal sacramentum.