Ephesians 4:29

The fourth exhortation is to speak good things as well as to do good things (Ephesians 4:28). Anything that injures others or causes dissension in the body is unwholesome (Gr. sapros, rotten, defiling). Christians should use words to build up people rather than to tear them down. Words can give grace (help) in the sense that they communicate encouragement and direction and thus enable the hearer to do right.

"It is said that a man once came to Mohammed and asked how he could make amends for falsely accusing a friend. Mohammed told him to put a feather on every doorstep in the village. Next day he told the man to collect them. ’But that is impossible,’ said the man, ’the wind has scattered them beyond recall!’ The prophet replied, ’So is it with your reckless words.’" [Note: Morris, p. 146.]