"But now you must get rid of all such things - anger, wrath, malice, slander, and abusive language from your mouth. Do not lie to one another, seeing that you have stripped off the old self with its practices and have clothed yourselves with the new self, which is being renewed in knowledge according to the image of its creator. In that renewal there is no longer Greek and Jew, circumcised and uncircumcised, barbarian, Scythian, slave and free; but Christ is all and in all!" Colossians 3:8-11
This is a call to be the new person that Christ has made us to be. In essence, we are to live differently in the world from the unbeliever. On the one hand we do show what it means to live the new life that Christ has brought to us. On the other hand, we do make the world to be a better place by living the ways Jesus had espoused for us.
In addition, I believe that in "putting on" this new self, we are a witness to the world for Jesus Christ. If we do not live differently, how can we demonstrate what it means to be a follower of Christ? We can say all that we want about Jesus, but we also have to walk the talk.
I invite you to reflect on your own life and see how much public witness you do give to Christ by how you live. You may want to read the entire passage which is Colossians 3:1-11. May God's blessing be upon your preparation for worship this Sunday.