I listened to the video below but 1 Peter says Christ Himself went and preached to them who are now in prison unless because it came after the Spirit, it means He preached through the Holy Spirit in Noah, but why does it use the word formerly if not all of them are still condemned or unrighteous? Also, how do we know the ark was being built for 120 years?
Video link: http://www.suscopts.org/diocese/bishop/bible-study/first-epistle-of-peter/session-03/
1 Peter 3:18-20 (NKJV)
"For Christ also suffered once for sins, the just for the unjust, that He might bring us to God, being put to death in the flesh but made alive by the Spirit, by whom also He went and preached to the spirits in prison, who formerly were disobedient, when once the Divine longsuffering waited in the days of Noah, while the ark was being prepared, in which a few, that is, eight souls, were saved through water."
All souls were formerly disobedient, but the faithful, such as Noah, his wife, three sons and their wives believed God and were saved from the flood. The souls of those who were disobedient and mocked Noah remain imprisoned. Emerging out of the water of the flood is also symbolic of the Mystery of Baptism, which gives life and salvation.
Based on Genesis 6:3, some Bible scholars believe that 120 years could be the length of time for building the ark. This is one of several interpretations.