The basic frame for 1 Peter 3:18-22 is that our purpose in this fallen world is to sanctify ourselves as priests so that we may minister the grace of God to this world that is perishing.
Our sanctification requires suffering (both our own and that of others) because only through suffering can we learn trust in God and empathy for others, precisely the qualities that underlie the two great commandments.
Oddly enough, suffering has a sanctifying effect regardless of whether it comes as a result of wrongful persecution, our own wrongdoing, or even accident. It's preferable that we avoid wrongdoing, however, because we have been called to transformation.
This mystery is the subject of 1 Peter 3:18-22, which stacks several dramatic images to drive home the point that sanctification, unlike justification, is a matter of transformation:
- The Spirit hovering over the waters before God spoke the world into being
- The ark floating on the flood waters before God brought forth a purged world
- The circumcised heart of the believer submerged in the waters of baptism
- The proclamation of Jesus to the unclean spirits in Tartarus before his ascension
The entire passage, which is very tightly argued, assumes that the reader is intimately familiar with each narrative referenced and understands how these narratives would "stack" to form a coherent whole. Here's a paraphrase that might help:
Christ our Lord put our sin to death in his body on the Cross, after which he proclaimed his authority over the unclean spirits in Tartarus, a prison for human-divine entities whose physical forms perished in the Flood, from which God spared a remnant of humanity who entered into the Ark, the germ of a new beginning, which corresponds to baptism whose waters are the outward confirmation of a circumcised heart and rebirth as a new person (see "Evangelion: The Meaning of Baptism" posted February 2011).
This passage of scripture is unparalleled as a key to understanding how everything fits together.
