"By the grace of God" Jesus tasted death "for every one". In his plan of salvation, God ordained that his Son should not only "die for our sins" but should also "taste death", experience the condition of death, the separation of his soul from his body, between the time he expired on the cross and the time he was raised from the dead. The state of the dead Christ is the mystery of the tomb and the descent into hell. It is the mystery of Holy Saturday, when Christ, lying in the tomb, reveals God's great sabbath rest after the fulfilment of man's salvation, which brings peace to the whole universe.
Source: Catechism of the Catholic Church (Vatican.va)