The Spirits in prison, to whom Jesus made proclamation, have been a matter of dispute and confusion for centuries. Who are these ‘spirits’ and when was it when Jesus preached to them? The passage, located, in 1 Peter 3:18-20, has traditionally been understood in three primary ways:
Option 1: Jesus preached, in some preincarnate state prior to his birth, to the spirits, who are the disobedient persons who failed to get on the boat when Noah preached;
Option 2: Jesus preached, during the conscious intermediate state between his death and his resurrection, to the spirits (either the disobedient persons or the sinful angels);
Option 3: Jesus preached, after his resurrection from the dead, to the spirits in prison (i.e., the angels who sinned).
All three of these options have been argued by expositors over the last two thousand years. How can we deduce which option is the most likely meaning of 1 Peter? Lets begin with some important points. 1 Peter 3:18 should be read as saying that Jesus was put to death but was made alive (via resurrection) in/by the spirit. The contrast of ‘being put to death’ and ‘being made alive’ elsewhere clearly denotes death and bodily resurrection (cf. 1 Cor. 15:22; Rom. 4:17; 8:11; John 5:21; 2 Kings 5:7 LXX). The beginning of 3:19 (“in which also he went”) indicates that it was in Jesus’ resurrected state that he made said proclamation. This rules out options 1 and 2.
The reference to the ‘spirits’ could mean a number of things. It would be odd to refer to human beings as spirits (although cf. 1 John 4:1). However, angels are described with this term within the Second Temple period in a few important passages:
But to which of the angels has He ever said, “sit at My right hand, until I make your enemies a footstool for your feet?” Are they not all ministering spirits, sent out to render service for the sake of those who will inherit salvation? (Heb. 1:13-14)
Who makes his angels spirits, and his ministers a flaming fire (Psa. 104:4 LXX; quoted in Heb. 1:7)
Micaiah said, “Therefore, hear the word of the LORD. I saw the LORD sitting on His throne, and all the host of heaven standing on His right and on His left. The LORD said, ‘Who will entice Ahab king of Israel to go up and fall at Ramoth-gilead?’ And one said this while another said that. Then a spirit came forward and stood before the LORD and said, ‘I will entice him.‘ (2 Chron. 18:18-20)
The spirits (angels) in prison seem to be those who were disobedient during the flood of Noah (1 Pet. 3:20). This episode appears in Gen. 6:2-4, where the “sons of God” refer to disobedient angels. This reading is confirmed by the other occurrences of the “sons of God” (b’ne haelohim) in the OT (cf. Job 1:6; 2:1; 38:7; Psa. 89:6; Dan. 3:25). Further NT testimony for this can be found in Jude 6 and 2 Peter 2:4.