These verses continue to outline the challenge issued in the preceding section-that the transformed life should be obvious to all. Again, Paul deals with the tongue, described by James as ″a world of evil among the parts of the body″ that often ″corrupts the whole body″ (James 3:6). ″It is a restless evil, full of deadly poison″ (James 3:8).

Jesus taught that it is not what goes into a man's mouth but what comes out of it that makes a man unclean, because it is the output of an unclean heart (Matthew 15:11, 18-20). He also warned that we will be judged for every careless word, and that the total output of our speech will acquit or condemn us (Matthew 12:36-37).

″Unwholesome talk″ includes vulgarity, slander, and contemptuous speech. This must be replaced by wholesome speech that builds up and encourages (Ephesians 4:29).

Putting off the old self includes getting rid of ″all bitterness, rage and anger, brawling and slander″, and ″malice″ (v. 31). Anger can explode into rage or freeze into bitterness. Brawling and slander are the works of a quarrelsome person, and malice is the result of evil in the heart. These are the works of the old man and have no place in the Christian's life. Instead, the believer must put on kindness, compassion, and a forgiving heart. The new man must treat others the way God has treated him. He must not be like the unmerciful servant who, having been forgiven an enormous debt by his kind master, went on to treat his fellow servant-who owed him a much smaller debt-harshly (Matthew 18:21-35). God has forgiven us ″for Christ's sake″ (Ephesians 4:32 KJV). Charles Spurgeon advises those who find it difficult to forgive another to do it at least for Christ's sake.

Kindness and forgiveness are characteristics modelled after God; we are motivated by Christ and enabled by the Spirit who produces this godly fruit (Galatians 5:22-23) in us.

When we fail to put off the old man and his sinful manifestations and to put on the new man, the Holy Spirit with whom we were sealed is grieved (Ephesians 4:30). John Stott notes that the indwelling Spirit is grieved by anything that is ″incompatible with . . . purity or unity″ that comes from God and should characterise Christians.