Remember that this entire section addresses how saving grace transforms our lives as a testimony to the world of the saving power of the gospel of Jesus Christ. Your life either is an advertisement encouraging people to repent and believe in Jesus Christ or a walking contradiction, giving Jesus’ enemies occasion to blaspheme His fair name because your life shows that the gospel has no power to change a person’s life. There is an evangelistic reason why grace instructs us to live as our text instructs, but the ultimate goal is the glory of God.