Romans 12:2 Do not conform any longer to the pattern of this world, but be transformed by the renewing of your mind.
Who are you? Usually we will answer the question with information about where we work, are we married, how many children do we have, etc. However, the most important thing is that you are a new creation with a new nature and are being transformed into the image of Christ.
The Greek word translated “do not conform” is a word which means “the act of an individual assuming an outward expression that does not come from within him, nor is it representative of his inner heart life.” The world can be defined as all the thoughts, attitudes, worldview, and values which are opposed to the things of God. When we, as Christians, conform to the pattern of this world it is an unnatural act, not representative of who we are in our inner being as a regenerated, recreated child of God.
The Greek word translated “be transformed” means “the act of a person changing his outward expression from that which he has to a different one, an expression which comes from and is representative of his inner being.” We get our word “metamorphosis” from this Greek word. In his book, Mere Christianity, C. S. Lewis asked: “If Christianity is true why are not all Christians obviously nicer than all non-Christians? He answers his question: “‘Niceness’—wholesome, integrated personality—is an excellent thing … But we must not suppose that even if we succeeded in making everyone nice we should have saved their souls. A world of nice people, content in their own niceness, looking no further, turned away from God, would be just as desperately in need of salvation as a miserable world—and might even be more difficult to save.” Lewis concludes: “For mere improvement is no redemption, though redemption always improves people even here and now and will, in the end, improve them to a degree we cannot yet imagine. God became man to turn creatures into sons: not simply to produce better men of the old kind but to produce a new kind of man.”
If we are “in Christ”, we are not better, improved copies of our old self, but we are a new creation, sons of God with a new nature. When we conform to the pattern of this world it is unnatural to us, is not representative of the new person we are inside. Who are you? You are a child of God, being transformed into His glorious image.