The manner of exhortation regarding believers walk and talk describes more than external behavior. It indeed includes external behavior but it is a behavior that stems from the mystery of God, that is Christ in you. He instructs us in chapter 2 that as you received Christ Jesus the Lord, so walk in him. The significance of this understanding is that Christianity is not merely a change in behavior. Christianity is a change in your nature, and therefore it results in a change of behavior. It is always in that order and never the other way around.