He then uses an example whose meaning is still being debated--comparing the rescue from the flood with rescue from sin by baptism. God waited patiently while Noah built the ark that would save eight persons. Baptism is an appeal to God for a good conscience, through the resurrection of Jesus Christ.
Rather than trying to be the person that will finally settle the arguments over this flood/baptism tie, I'm instead going to return to what seems to be the main purpose--to speak to Christians who are suffering unjustly. Here's what Beverly Gaventa says in Texts for Preaching:
In the face of any suffering, whether caused by human inhumanity, by disease, or by nature, the available answers always fall short. What Christians can assert with 1 Peter, as with Christians of every time and place, is that God stands with those who suffer and that God ultimately triumphs over that suffering.