“For Christ also suffered once for sins, the righteous for the unrighteous, to bring you to God. He was put to death in the body but made alive in the Spirit” (1 Peter 3:18 NIV).
This reference to Christ “being put to death in the flesh but made alive in the spirit” represents one of the more interpretively challenging passages in this epistle. Perhaps the most straightforward treatment of this verse has been offered by the following author…
“The statement that Christ was ‘made alive in the Spirit,’ therefore, means simply that he was raised from the dead, not as a spirit, but bodily (as resurrection always is in the NT), and in a sphere in which the Spirit and power of God are displayed without hindrance or human limitation (cf. 1:21).” (1)
Another Biblical scholar addresses the cultic interpretations of this passage that erroneously claim that Jesus’ resurrected body was not flesh, but “spirit” (or immaterial)…
“To interpret this as proof of a spiritual, rather than a physical resurrection, is neither necessary nor consistent with the context of this passage and the rest of Scripture. The passage is best translated, ‘He was put to death in the body but made alive by the [Holy] Spirit’ (NIV). The passage is translated with this same understanding by the New King James Version and others. God did not raise Jesus a spirit but raised him by his Spirit.
The parallel between death and being made alive normally refers to the resurrection of the body in the New Testament. For example, Paul declared that Christ died and rose and lived again (Rom. 14:9), and ‘He was crucified in weakness, yet he lives by the power of God’ (2 Cor. 13:4a NIV). The context of 1 Peter 3:18 refers to the event as ‘the resurrection of Jesus Christ’ (3:21). This is everywhere in the New Testament understood as a bodily resurrection (Acts 4:33; Rom. 1:4; 1 Cor. 15:21; 1 Peter 1:3; Rev. 20:5)…
We must also keep in mind that however we interpret 1 Peter 3:18, it must be consistent with what other verses say about the resurrected Christ. In Luke 24:39 the resurrected Christ said, ‘See My hands and My feet, that it is I Myself; touch Me and see, for a spirit does not have flesh and bones as you see that I have’ (Luke 24:39 NIV). The resurrected Christ testifies in this verse that he is not a spirit and that his resurrection body is made up of flesh and bones…
The resurrected Christ also ate physical food on four different occasions to prove he had a real physical body (Luke 24:30; 24:42–43; John 21:12–13; Acts 1:4). It would have been deception on Jesus’ part to have offered his ability to eat physical food as a proof of his bodily resurrection if he had not been resurrected in a physical body.” (2)
(1) E. G. Selwyn, The First Epistle of Peter, p. 197. Quoted in Notes on 1 Peter 2023 Edition, Dr. Thomas L. Constable. https://www.planobiblechapel.org/tcon/notes/html/nt/1peter/1peter.htm
(2) Norman L. Giesler and Ron Rhodes, When Cultists Ask A Popular Handbook on Cultic Misinterpretations [note on 1 Peter 3:18]. Baker Books, 1997