Throw off your old evil nature and your former way of life, which is rotten through and through, full of lust and deception. Instead, there must be a spiritual renewal of your thoughts and attitudes. You must display a new nature because you are a new person, created in God’s likeness—righteous, holy, and true.
The exciting reality of Christianity is that a believer becomes a new person. In Ephesians 4, Paul contrasts the “old man” and the “new man.” The old man is a liar, while the new man tells the truth (Ephesians 4:25). The old man is always angry, but the new man controls anger and makes amends for it before the day is over (v. 26).
There are further contrasts between the old man and the new. The old man is stingy and steals, but the new man has a desire to work hard and give to others (v. 28). The old man uses abusive language, but the new man speaks words that encourage others (v. 29). The old man holds grudges and bitterness for years, but the new man is kind, tenderhearted, and forgiving (v. 32).
For you to say that you have become a Christian yet continue to lie, vent your wrath, steal, curse, and harbor unforgiveness is a contradiction in terms. As a Christian, you must put off your old self and put on the new self, which was created to be like God. In this way, you will live a life “worthy of your calling” (v. 1) by the grace God has given you through salvation.
Remember: You are a new person!