You don't think they were already aware of that, considering where they were?
To clarify further:
Things Hard to be Understood
1 Peter 3:18-20
“For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit: By which also he went and preached unto the spirits in prison; Which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water.” –
1 Peter 3:18-20
The following is by the late Pastor Nick Michalinos, Austin Avenue Baptist Church, Pasadena, Texas:
“Some have the idea that Christ, between His death on the cross and His resurrection three days later, went and preached to lost spirits who were imprisoned in the spirit underworld. However, this is not what these verses teach. The word ‘prison’ is used with regard to the spiritual realm (see
Revelation 20:3,7, Satan’s ‘prison’), the unseen spirit world, the Hadean world
(Luke 16:23-31) where lost spirits reside and are reserved unto ‘the day of judgment to be punished’
(2 Peter 2:9; Revelation 20:13-14).
“When was this preaching done? Our text states, ‘in the days of Noah…’ This occurred just before the flood. Christ did not go down to Hades and preach the gospel to ‘spirits in prison.’ The preaching was done in ‘the days of Noah.’
“Who did the preaching in that day? By continuing the flow of thought from 1 Peter 3:18 into verse 19 we see that ‘Christ … by the Spirit … went and preached.’ We are told in
Genesis 6:3, ‘And My Spirit shall not always strive with man.’ From this we can see that Christ through the Holy Spirit was striving with the people just before the flood. He used the ‘preaching’ of Noah, who was ‘a preacher of righteousness’
(2 Peter 2:5). So we have Christ sending the Spirit, and the Spirit spoke through a human instrument, Noah, and Noah preached to the people.
“What was the response to the Spirit’s striving through Noah’s preaching? It is said they were “disobedient”
(1 Peter 3:20). They resisted the Spirit
(Acts 7:51).”
See also commentary on
1 Peter 4:6.
Things Hard to be Understood
1 Peter 4:6
“For for this cause was the gospel preached also to them that are dead, that they might be judged according to men in the flesh, but live according to God in the spirit.” –
1 Peter 4:6
“You notice it doesn’t say the men who were dead. It says it was preached to them that are dead. The meaning is that those that are now dead had the Gospel preached to them while they were yet living. The third chapter of 1 Peter has something on practically the same subject, verses 18,19, and 20: ‘For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit: by which also he went and preached unto the spirits in prison; which sometime were disobedient, when once the longsuffering of God waited in the days of Noah, while the ark was a preparing, wherein few, that is, eight souls were saved by water.’ The answer is that Christ went in His Spirit--—the Spirit of Christ, the Spirit of God--—the Holy Spirit, and preached through Noah in the days before the flood to those who now are spirits in prison. It does not mean that He has gone to them since they entered the prison and preached there to them. There is mystery about these passages, but this seems to be the true explanation” (William L. Pettingill).
