1 Peter 3:19

“By which also he went and preached unto the spirits in prison.] Various are the senses given of this passage: some say, that Christ, upon his death, went in his human soul to hell; either, as some, to preach to the devils and damned spirits, that they might be saved, if they would; and, as others, to let them know that he was come, and to fill them with dread and terror; but though hell may be meant by the prison, yet the text does not say that he went unto it, or preached in it; only that the spirits were in it, to whom he sometimes went, and preached; nor is his human soul, but his divine nature meant, by the Spirit, by which he went and preached to them: and as for the ends proposed, the…”

“By which - Evidently by the Spirit referred to in the previous verse - ἐν ᾧ en hō - the divine nature of the Son of God; that by which he was “quickened” again, after he had been put to death; the Son of God regarded as a Divine Being, or in that same nature which afterward became incarnate, and whose agency was employed in quickening the man Christ Jesus, who had been put to death. The meaning is, that the same “Spirit” which was efficacious in restoring him to life, after he was put to death, was that by which he preached to the spirits in prison. He went - To wit, in the days of Noah. No particular stress should be laid here on the phrase “he went.” The literal sense is, “he, having…”

“By which Spirit he preached - Through the ministry of Noah. To the spirits in prison - The unholy men before the flood, who were then reserved by the justice of God, as in a prison, till he executed the sentence upon them all; and are now also reserved to the judgment of the great day. 1 Peter 3:20”

“3:19-20 This difficult passage has been widely interpreted in three ways: (1) One interpretation holds that it refers to the spirits of people who have died and that Christ, after his resurrection, preached the Good News to these spirits. However, the idea that people might hear the Good News and respond after their deaths is not found elsewhere in the New Testament, and this meaning of spirits is not the most likely. (2) A second interpretation sees 3:19-20 as describing Christ’s preaching through Noah to people who are now spirits in prison. This interpretation does justice to 3:20 but does not fit well in the discussion of Christ’s death and resurrection (3:18). (3) In the third…”

“By which: Pe1 1:11, Pe1 1:12, Pe1 4:6; Neh 9:30; Rev 19:10 in: Isa 42:7, Isa 49:9, Isa 61:1; Rev 20:7 1 Peter 3:20”