Living for God
4 Therefore, since Christ suffered in his body, arm yourselves also with the same attitude, because whoever suffers in the body has finished with sin. 2 As a result, they do not live the rest of their earthly lives for evil human desires, but rather for the will of God. 3 For you have spent enough time in the past doing what pagans choose to do – living in debauchery, lust, drunkenness, orgies, carousing and detestable idolatry. 4 They are surprised that you do not join them in their reckless, wild living, and they heap abuse on you. 5 But they will have to give account to him who is ready to judge the living and the dead. 6 For this is the reason the gospel was preached even to those who are now dead, so that they might be judged according to human standards in regard to the body, but live according to God in regard to the spirit.
Whenever we see a "therefore" in scripture the text usually moves on to an application as a result of the previous teaching. In this case Peter is teaching them again in regard to suffering and what they can expect. If Jesus suffered, they shouldn't be surprised that they are going to suffer too. So in preparation he is trying to give them the right perspective by having them adjust their attitude.
He also says something quite interesting about the process. He says, "whoever suffers in the body is finished with sin". What does he mean by being finished with sin? Does that mean they will never sin again? No, that can't be so, as we will struggle against our sinful nature until we die. The verses that follow give us a clue to what this might mean. Peter says that in their past, they spent much time living like the pagans did. He uses examples of lust, drunkenness, carousing, and orgies. You get the point! I think what he might be saying is that as they leave their old lifestyle, it won't be easy. After all they have trained their bodies to live like this and the bondage needs to broken. Second, they will suffer the abuse from those who stay in the lifestyle will heap on them. As they sought to pursue their new life in Christ, others would be surprised at the change and maybe even resent it.
Peter says that they will be judged for their behavior, so don't worry if they mock you! And who knows maybe the disciples' own transformation might be a means God uses to warn these unbelievers of the eventual consequences of their behavior. Bottom line is that as we leave an old lifestyle of sin, whatever that was for each of us, it won't come without some cost. But as we suffer for it, we will crucify the flesh with its desires. We will be freed to live according to the Spirit's guidance and leading. If you are suffering today, remember suffering always has a purpose. It draws us closer to Christ and farther away from sin, as we allow it to mold and shape us.