The harrowing of hell (3:19) has attracted the attention of poetic and illustrative imaginations throughout history--understandably so, since it seems to answer two provocative questions with an underdeveloped premise.
What becomes of people who died before Jesus' advent among us? And what was Jesus' condition between his death on the cross and his resurrection? During that time, Jesus descended among the dead and proclaimed the good news of salvation, according to traditions that hark back to 1 Peter 3:19. As a result, some among them were set free from death along with Jesus.
It's hard to know how the dead reckon time, so the idea that Jesus might have "spent three days" preaching among the dead involves some peculiar calculations. Likewise, nobody can say just what the effects of Christ's proclamation to the imprisoned spirits might have been; Scripture asserts that Jesus did preach to the departed, but does not specify the extent of his preaching's effects. Interpreters may combine this brief allusion with Matthew 27:52 ("many bodies of the saints who had fallen asleep were raised") and Ephesians 4:8-9 ("he made captivity itself a captive") to flesh out a picture in which the triumphant Christ releases the dead from their imprisonment in Hell, but such a synthetic inference provides more detail than any of the individual passages.
If we prescind from overconfident inferences about the time and location of Christ's ministry to the saints of antiquity, we still have much to observe relative to this passage. The emphasis in this context, for example, falls less on the details of Christ's action than on the purpose of Christ's mission. The portion of today's lesson that runs from 3:18 to 3:22 emphasizes with fourfold repetition God's determination to bring people to safety: by preserving humanity through the ark, by Jesus' self-giving on the cross, by the effects of baptism, and by Jesus' ministry to the dead. No people have been excluded from God's saving grace--not even the dead. All through time, God has sought to make salvation available.
God saves us, however, not by arbitrarily flipping a switch next to our names. The effective grace of God alters us in ways that conform us to our greatest goodness, articulated in God's will for us. That will, however, comes to expression in such goodness as 1 Peter describes in the first half of the passage: gentleness, reverence, and integrity ("clear conscience")--the "genuine faith" that survives testing and suffering (1:7, 3:14-17). To the extent that our lives are characterized by these qualities, they bespeak God's presence, and God's own character, and they testify to our living as the royal priesthood God has made of us.
Thus, instead of construing today's pericope as a schematic of Christ's itinerary between Golgotha and resurrected glory, or as a mandate to seek out misery in order to acquire a blessing, the passage as a whole narrates the frame within which believers' hopes and sorrows will appropriate intelligibility. Disciples seek the meaning of their whole lives in the way of life that Christ reveals to us; we commit ourselves to living out that way in public, in our interactions with hostile authorities and incredulous neighbors (as he did, possibly to the extent of yielding our lives). We do not thus earn God's favor, as though suffering were a brutal inquisitorial exam for us; rather, we show the world, and ourselves, and our God, the grace of God already working in us. This is the account that 1 Peter urges us always to be ready to give (3:15, "make your defense to anyone who demands from you an accounting for the hope that is in you" (NRSV); "give an answer to everyone who asks you to give the reason for the hope," NIV). We surely ought to be better able to explain our faith in persuasive words, but a far more important (and often far more persuasive) explanation can be inferred from lives illumined by the Gospel.
The reading acknowledges that others who hold authority over us may use that authority abusively (though we minimize that risk if we do not provoke them to hostility); in the face of official persecution, disciples of Jesus stand under an even greater obligation to demonstrate their innocent gentleness. They may not appeal to the schoolyard rationalizations that bullies hit them first, or that they had no choice. Jesus did not return violence for the violence done to him, even though the soldiers and bystanders struck him first. And disciples always have the choice to follow Jesus by upholding the integrity of their faith when officials threaten them. (It should not need saying that for just these reasons, followers of a wrongfully tortured, crucified Lord must never under any circumstances inflict torture on others.) This passage rightly knits together the expectation that believers will protect the integrity of their faith even at the cost of their lives, with the possible positive effects of their persistence: a testimony to shame the evildoers, and an opportunity to partake in the cleansing effects Christ's resurrection.
The resurrection brings us back around to the subject of the significance of Christ's preaching to the departed. Christ was wrongfully put to death by human cruelty, but even this evil could not limit God's grace; Christ's faithfulness up to and beyond death make salvation available to all those in every generation who turn to him in hope. It is fitting that here, Jesus' gospel reflects God's grace; the gospel is grace revealed (as it were), and grace is the gospel in operation. Jesus unfolds the way that God's purpose runs and shows us how to align ourselves with that purpose, by refusing to cede to our tormentors the victory of making us turn from good. With that refusal of evil and affirmation of mercy, God's grace abounds to all who have lived and died before Jesus was born, and to us also who draw near to Jesus in order to partake of, and share in offering, the mercy by which we are saved.