1 Peter 3:18-22
For Christ also suffered once for sins, the righteous for the unrighteous, to bring you to God. He was put to death in the body but made alive in the Spirit. 19 After being made alive, he went and made proclamation to the imprisoned spirits – 20 to those who were disobedient long ago when God waited patiently in the days of Noah while the ark was being built. In it only a few people, eight in all, were saved through water, 21 and this water symbolises baptism that now saves you also – not the removal of dirt from the body but the pledge of a clear conscience towards God. It saves you by the resurrection of Jesus Christ, 22 who has gone into heaven and is at God’s right hand – with angels, authorities and powers in submission to him.
Peter today talks about the resurrected Jesus preaching to imprisoned spirits. This is a very obtuse verse without precedent in any other place in the bible. It would be nice to think people got a second chance who weren't around in Jesus' day. But there is no other evidence in the scripture that people get a second chance after death. Hebrews 9:25, "Just as people are destined to die once, and after that to face judgment."
So if that is the case what does it mean? Here are 4 common views theologians have given
View 1: Perhaps what is meant by “preaching to the spirits in prison” could be Christ or God preaching through Noah (2 Pet 2:5 or 1 Pet 3:20) to that wicked generation and even though Noah preached repentance, nobody listened and today these humans are imprisoned awaiting the final judgment (Rev 20:11-15).
View 2: Others believe that during the short interval between Jesus’ death and resurrection, He descended into hell to preach to these lost souls and proclaimed His victory to those who died in the flood and all those souls who died up to the period of the flood.
View 3: Yet others feel that Christ preached to these spirits or souls between His death and resurrection and it was directed to the fallen angels because angels, either holy or fallen, can be referred to as the “sons of God” (Gen 6:2, 4; Job 1:6, 2:1) and these fallen spirits are presently imprisoned (of which is close to the view mentioned in the previous paragraph).
View 4: A final view is that Christ personally proclaimed His victory over Satan, and subsequently Satan’s associates (fallen angels or demons) but He did so after His resurrection but before His ascension into heaven.
As you can see they vary widely. That is why an important rule in biblical interpretation is the unity of the bible. We don't let one reference, which is vague to begin with, be a basis for something like purgatory for example. What this verse can inspire us to do is to proclaim the gospel while people are alive. As people receive the free gift of God and are baptized they are washed clean. God's desire is that all people would be saved in this life. God's grace is extended to all who would receive it. Let's make the most of this grace by living a life worthy of our calling
Until Jesus calls us home.