In 1 Peter 3:13-22, Peter continues to address the suffering that his congregations are facing. In fact, this passage of Scripture is remarkably similar to last week's reading from 1 Peter (2:19-25). In that passage, Peter tells his congregations that Christ is their example to live by. Therefore, because Christ quietly endured unjust suffering, they should as well. In the passage for this week, Peter seeks once again to show that suffering does not equal God-forsakenness. In fact, contrary to what common sense might lead us to believe, these congregations are blessed if they suffer for the sake of righteousness. Therefore, instead of fearing whatever harm might come to them, they are to sanctify Christ as Lord in their hearts.
This idea of sanctifying Christ as Lord in one's heart is somewhat of an odd expression. This is the case because to sanctify means to make holy or to set apart for a specific, usually divine, purpose. Usually, it is God who performs this action, setting apart certain people or objects for his own holy purposes. However, in this verse, Peter calls upon his congregations to do the sanctifying of their Lord. In this way, the command that Peter gives is similar to the second line of the Lord's prayer; "hallowed be your name". The word translated "hallowed" in the Lord's prayer is actually the same root word in Greek that is used in this verse in 1 Peter. When we pray that line of the Lord's prayer, we are praying that God's name be sanctified. Interestingly, the Lord's prayer then ties the santifying of God's name to things like God's kingdom coming and God's will being done on earth, people having enough to eat, forgiveness being lived out, and temptation being avoided. In other words, God's name is hallowed, Christ is sanctified as Lord in our hearts, when all of these things take place, when human beings live as God intended. Peter is encouraging his congregations to bring glory to God by witnessing to the hope that they have in Jesus Christ even as they endure pain and suffering.