The Diocese of Bismarck in North Dakota took a moment this week to remind the faithful of the significance of the Triduum, which began on Holy Thursday.

“As Lent concludes at the start of the Mass of the Lord's Supper on Holy Thursday, we begin the great Paschal Triduum,” the diocese posted on Facebook. “This shortest season of the Church year points us toward Jesus' ultimate sacrifice for us and the joy of Easter that we should carry with us every single day.”

Holy Thursday is significant because it was the night of the Last Supper, when Jesus instituted the Sacrament of the Eucharist, offering his body and blood to his disciples in the form of bread and wine, according to the U.S. Conference of Catholic Bishops.

It is also the day Jesus instituted the priesthood, entrusting to his apostles the legacy of the church, the USCCB said. The celebrant during Holy Thursday Mass washes the feet of several participants. This is seen as an act of humility that replicates what Jesus did with his disciples.

Easter marks the day of the Resurrection, the cornerstone of the Christian faith, according to Christianity.com. It comes three days after his crucifixion. The Resurrection confirmed that Jesus was the true son of God and showed to all who believe in him, they will be granted eternal life in Heaven.