After Christ chose to die on the cross, His body was laid in the new tomb for three days (Biblical account of three days) and His Spirit went to the place where the spirits of people of the time of Noah were in prison. All those people perished by the universal flood because of their unprecedented sin against God. Let’s read 1 Peter 3:18-20 AMP:
18 For indeed Christ died for sins once for all, the Just and Righteous for the unjust and unrighteous [the Innocent for the guilty] so that He might bring us to God, having been put to death in the flesh, but made alive in the Spirit; 19 in which He also went and preached to the spirits now in prison, 20 who once were disobedient, when the great patience of God was waiting in the days of Noah, during the building of the ark, in which a few, that is, eight persons [Noah’s family], were brought safely through the water.
The purpose of Jesus’ (the Spirit) descending to the place of the spirits in prison is at least twofold: First, all our sins that are placed on Jesus through His death were met at the place where the spirits in prison were (the time of Noah represents the whole history of sinful soul against God when He saw the whole earth was so corrupted by sin that He decided to wipe out the whole souls from the surface of the earth by sending water). Jesus, the Son of God, was separated from God, the Father, for the first time because of our sins. Jesus’ agony was in this separation from God who is always with Jesus (God) from eternity to eternity. God saw our sins placed on Jesus and cast Jesus away due to our sins at the moment of His declaration of death on the cross (see “And Jesus, crying out with a loud voice, said, ‘Father, into Your hands I commit My spirit.’ Having said this, He breathed His last.” Luke 23:46 NASB).
Second, during the time with the spirits in prison, Jesus (the Spirit) proclaimed to them in order to reveal God’s omnipotence. Since Christ is God of living as the Scripture declares in Luke 20:18, preaching to them wouldn’t do anything to them because of their spiritual blindness even after their spirits are alive (the word, “sleeping” is used interchangeably) at the moment of death separated from their physical bodies. Most importantly, Hebrews 9:37 NIV says, “Just as people are destined to die once, and after that to face judgment.” Today is the day of salvation (see 2 Corinthians 6:2). – T