Holy Week is the highest point of the liturgical year and the most solemn and joyful week in Christianity. Compared to Christmas, it is even more sacred! This is due to the fact that Holy Week honors the last week of Our Lord's life. Easter Sunday marks the conclusion of Holy Week, which started on Palm Sunday, the day Jesus made his last entry into Jerusalem.
The seriousness intensifies as Holy Week nears its conclusion. The most solemn period of the liturgical year lasts from sunset on Holy Thursday until sunset on Easter Sunday. The term Easter Triduum, which is also called the Sacred Triduum or Paschal Triduum, refers to this three-day period. "Triduum" is derived from the Latin term triduum, which is formed by the combination of tris + dies.
The Sacred Triduum is essentially a single, grand celebration that narrates the final three days of Jesus' earthly life, including his Passion and Resurrection—the moments when the Lamb of God gave his life in order to pay the price for our sins. The reason it is called the "Paschal Mystery" is that it is the consummate realization of the ancient Jewish Passover, also known as Pasch, which commemorated the event by which God delivered the Jews from Egyptian slavery. That same evening, the destroying angel "passed over" the homes marked with the blood of the Passover Lamb, saving those covered by the blood. The lamb, which was spotless, was slain and eaten during the Passover supper.Â
This was how Jesus' actions at the Last Supper were symbolized in the Old Testament. He presented himself on Calvary, the site of the sacrifice made to free us from the bonds of sin, and as the Paschal Lamb. We eat the sacrifice made to atone for our sins when we partake of the Holy Eucharist. Therefore, God's plan of salvation for the fallen human race via the suffering, death, and resurrection of the God-man Jesus Christ is known as the Paschal Mystery.