Like Paul in the Pastoral Epistles, 1 Peter addresses domestic relations. In keeping with the cultural and social conventions of the time (in both Hebrew and Latin culture) the husband was the head of the household. In modern times we often hear the restrictions of "accepting the authority" and miss the grace displayed in the same passage. Men (7) are to honor their wives as "heirs of the gracious gift of life." That is to say that men and women have equal standing in faith and in the context of a household of faith -- each husband and each wife ought to treat one another as embodying the holy presence of Christ. I have long believed that those who "enforce" the submission/authority passages are those who are the most unwilling to treat one another as bearing the incarnate Christ. 1 Peter's appeal to modest in dress and trusting in inward adornment is a reminder to us all that God is not impressed with our fancy clothes and cleaned up externals -- God looks at the heart.
3:8 and following returns to the central theme of 1 Peter; the theme of being patient in suffering. Here he makes an excellent point -- again, remember, that the people reading this letter in the late first century are enduring violent persecution at the hands of the government and "religious" opponents. The Christians are suffering simply for being Christians -- a situation that exists in many places in the world even today. 1 Peter suggests that if we are punished for doing something wrong we have received our just due. However, if we suffer because we have done right (that is followed Jesus Christ) then we are more like him in that moment then we ever imagined we could. Jesus was innocent, blameless and sinless and yet suffered the crucifixion for us all. Many early Christians believed that martyrdom and enduring suffering because one was a follower of Christ was not "evil" but counted it was counted as a privilege to suffer at Christ did.