The “spirits in prison” are mentioned in the context of what Jesus did in the time between His death and resurrection. First Peter 3:18–20 says, “He was put to death in the body but made alive in the Spirit. After being made alive, he went and made proclamation to the imprisoned spirits—to those who were disobedient long ago when God waited patiently in the days of Noah while the ark was being built.” Note that Jesus’ body was dead and awaiting resurrection, but He was spiritually alive during the time that His body was in the grave. As background, please read our article on “Where was Jesus for the three days between His death and resurrection?”
We know three things for sure about the spirits mentioned in 1 Peter 3:19. They are incorporeal, they are imprisoned, and their sin was committed before the Flood. The verse also seems to indicate that Jesus visited the place of their captivity to make an announcement to them. Who exactly these spirits are has been the subject of some speculation through the years.
We take the view that the spirits in prison are fallen angels or demons. The spirits in prison cannot be holy angels, because they have not sinned and are not imprisoned. It is clear that not all the demons are imprisoned, for the New Testament gives many examples of demonic activity on earth. So the spirits in prison must be a select group of demons who, unlike the their demonic allies, are held captive.
What might be a reason for some, but not all, of the demons to be imprisoned? Jude 1:6 gives us an important clue: “The angels who did not keep their positions of authority but abandoned their proper dwelling—these he has kept in darkness, bound with everlasting chains for judgment on the great Day.” There are some fallen angels that committed an egregious crime of some kind; Jude 1:6 does not give details, but the demons’ sin was related to how they “did not keep their own position but deserted their proper dwelling.” Revelation 9:1–12, 14–15, and 2 Peter 2:4 also speak of a group of wicked angels that are currently bound.
The sin the spirits in prison committed could be the one in Genesis 6:1–4, which records the “sons of God” mating with the “daughters of men” and producing a race of giants, the Nephilim. If the “sons of God” were fallen angels, then the sin of Genesis 6 involved angels leaving the place where they belonged in an act of disobedience before the Flood—and that corresponds to what the apostle mentions in 1 Peter 3:19. It could be that the demons who cohabited with human women were imprisoned by God to prevent them from repeating that sin and to discourage other demons from trying it.
According to 1 Peter 3:19, Jesus “made proclamation” to these spirits in prison. The Greek word translated “proclaimed” or “preached” means “to publicly declare” or “to herald.” If the spirits are demons, then Peter says that Jesus went to the Abyss and proclaimed His victory to the fallen angels imprisoned there. They had lost, and He had won. The cross triumphs over all evil (see Colossians 2:15).
Another view of the identity of the spirits in prison is that they are the human spirits of those who perished in the flood of Noah’s day. As for Christ preaching to them, there are two interpretations: 1) Christ preached to them figuratively, in and through Noah, while they were in the flesh; and 2) Christ preached to them literally in between His death and resurrection. According to both interpretations, the spirits are called such because they were in a spiritual condition when Peter wrote; they were no longer in the flesh but lived in Hades.