Ephesians 4:29 Let no corrupt communication proceed out of your mouth, but that which is good to the use of edifying, that it may minister grace unto the hearers.
Context: Ephesians 4:22-24 to put off your old self, which belongs to your former manner of life and is corrupt through deceitful desires, 23and to be renewed in the spirit of your minds, 24and to put on the new self, created after the likeness of God in true righteousness and holiness.
From the lexicon: Corrupt communication=unwholesome word. Proceed=go forth. Good=useful, fitting. Edifying=building up. Minister=give. Grace=kindness.
Pulling it all together: The Bible has much to say about how we ought to guard what we say. James devotes a whole chapter to the topic of taming the tongue. Here Paul addresses the issue while admonishing us to put off the ways of our old selves and to put on our new created nature after the likeness of God. He goes on to admonish us to put away lying, anger, and stealing for such is giving place to the devil vv. 25-28. In short, let nothing unbecoming come from your heart and out of your mouth. Use your words to build and encourage others; not to tear down.
We cannot do this alone. Verse 23 gives us the key. Yield to the Spirit Who renews our minds, giving a whole new way of thinking–after God instead of ourselves.
Lord, I pray for grace to yield my thoughts and words to You so that You are glorified through them and that those around me will be blessed.