Peter’s discussion of suffering, which he has woven throughout 1 Peter, comes to a climax in this section. The thread of conduct that allows us to stand firm in God’s grace (1 Peter 5:12) and the thread that suffering does not mean you are outside of God’s grace (1 Peter 5:12) are tied together in these few verses (read about the importance of 1 Peter 5:12 here).
Peter begins in verse 12 by telling them not to be surprised by suffering. He can say this plainly now because he has already established that they were called “to do good in suffer, ” that Jesus is our example in how we handle suffering, and that their Christian conduct leads to suffering (1 Peter 2:21 and 4:4). Therefore, Peter has made it clear that the Christian life will include suffering. Thus Christians should not be surprised when they face it.