Jesus’ soul, united with his divinity, descended into hell (the abode of the dead), and remained there as long as his body lay in the sepulcher.
With regard to the state of the just in paradise, faith leaves no room for diversity of opinion. Both Scripture and Sacred Tradition clearly teach that, after his death, Christ’s soul descended into paradise. “I will penetrate to all the lower parts of the earth, and will behold all that sleep, and will enlighten all that hope in the Lord” (Eccles. 24:45). And Christ himself says: “For as Jonah was three days and three nights in the belly of the whale, so will the Son of man be three days and three nights in the heart of the earth” (Mt. 12:40). And Saint Paul: ““He ascended,” what does it mean but that he had also descended into the lower parts of the earth? (Eph. 4:9). And Saint Peter: “For Christ also died for sins once for all, the righteous for the unrighteous, that he might bring us to God, being put to death in the flesh but made alive in the spirit; “in which he went and preached to the spirits in prison” (1 Peter 3:18-19). And again: “he was not abandoned to Hades, nor did his flesh see corruption” (Acts 2:31).
These and other passages in Holy Scripture refer not only to Christ’s body, but also his soul. And the Church has always taught that while Christ’s body was in the grave, his soul was in paradise. And so have the saints of God in every age understood the words of the Apostle’s Creed: “He descended into hell.”
Christ descended into hell, not in the condition of a captive, but like a victorious general, who having defeated his enemies, enters the city in triumph and liberates those valiant and faithful soldiers who had been made prisoners of war. Jesus wished to bring to those holy souls the joyful news of their redemption which he had merited by his death. He wished to illuminate that place with his divine presence. He wished to show his divinity to those souls and make them joyful by changing that place into a veritable paradise. For so He called it when speaking to the good thief on the cross: “Truly, I say to you, today you will be with me in Paradise. (Lk. 23:43).