These next verses are contentious and have been scrutinized by people since they were written. There are several ways they might be understood on their own, but can those beliefs hold up in context of other Bible scripture?
1 Peter 3:18-20 Christian Standard Bible
18 For Christ also suffered for sins once for all, the righteous for the unrighteous, that he might bring you to God. He was put to death in the flesh but made alive by the Spirit, 19 in which he also went and made proclamation to the spirits in prison 20 who in the past were disobedient, when God patiently waited in the days of Noah while the ark was being prepared. In it a few—that is, eight people—were saved through water.
Some Christians believe these verses in 1 Peter prove humans have an immortal soul that lives independently from the physical body and is freed when the body dies. Likening our body to a coat that is slipped off at death with the soul going on to live without even losing consciousness or a thought, they believe humans go to be with God or are tormented in hell depending on what they did during their physical lives on earth. These Christians believe Jesus went down to hell to preach to the fallen Angels or to lost souls for three days after he was crucified, while his body was in the grave. Others, who believe they have an immortal soul, disagree with that assessment. Asking a few critical questions helps assess the meaning of the passage. How did Jesus preach to them? When did he preach to them? Who are the spirits being preached to? Make no assumptions and note the verses do not even contain the word hell. Paying close attention to verses 18-19, we discover that although Jesus’ body died, he was made alive by the Spirit. It was through the Holy Spirit that Jesus preached to the spirits in sin’s prison while Noah was building the ark, long before Jesus was crucified. The Holy Spirit preached to mankind through holy men of God. Noah is included as one of those, being called a preacher of righteousness. Jesus preached to the people Satin had imprisoned in sin, through Noah, before the flood destroyed them all. Does God have a plan that could save all of humanity? Is all humanity covered by Jesus’ sacrifice? When do those, who lived before Jesus lived, get to learn about him and accept the sacrifice he made for all of mankind?
2 Peter 1:21 King James Version
21 For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost.
2 Peter 2:5 King James Version
5 And spared not the old world, but saved Noah the eighth person, a preacher of righteousness, bringing in the flood upon the world of the ungodly;