The word paschal comes from the Hebrew word for Passover—the event in Exodus where the death angel passed over all the homes that had the blood of a lamb on the lintel and door posts but brought death to the firstborn in all houses that did not have the blood. The word mystery refers to something that cannot be known except by grace and revelation—a person cannot figure it out on his own (see 1 Corinthians 2:14).
Together, the terms are used to refer to the suffering, death, burial, resurrection, ascension, and exaltation of Jesus Christ The paschal mystery involves the final Passover Lamb who died so that God’s judgment will “pass over” those who have applied His blood by faith.
There is an emphasis on “mystery” in the Catholic Church; however, Protestants would also agree that the significance of Christ’s work cannot be grasped unless God should reveal it to the individual by grace. Paul explains: “For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God. For it is written: ‘I will destroy the wisdom of the wise; the intelligence of the intelligent I will frustrate.’ Where is the wise person? Where is the teacher of the law? Where is the philosopher of this age? Has not God made foolish the wisdom of the world? For since in the wisdom of God the world through its wisdom did not know him, God was pleased through the foolishness of what was preached to save those who believe. Jews demand signs and Greeks look for wisdom, but we preach Christ crucified: a stumbling block to Jews and foolishness to Gentiles, but to those whom God has called, both Jews and Greeks, Christ the power of God and the wisdom of God. For the foolishness of God is wiser than human wisdom, and the weakness of God is stronger than human strength” (1 Corinthians 1:18–25).
In summary, the term paschal mystery simply refers to the events of Christ’s death and resurrection and their significance for us, which we can only truly understand when our hearts are enabled to do so by God’s grace. For us who believe, the gospel is indeed the power of God, and Jesus’ death is the most wonderful, powerful, and important event in history. Others, who do not believe, see it differently. Richard Dawkins, one of the militant “new atheists,” says that the death of Christ for us is a disgusting thought and the idea of Jesus’ resurrection is silly and insignificant. Dawkins seems to go so far as to say that, even if Jesus did rise from the dead, it would have no meaning for him.
The fact of “mystery” explains how two people can look at the same events and come to such divergent conclusions—one is approaching them purely from the standpoint of human reason, and one is approaching them through insight given by God.