If the tongue had a general list of sins, what would they be? Anger, slander, folly, lies, rash judgments, and dirty/defiling speech. The little member is small but poisonous.
There is, Paul says, a foolish talking that is not convenient. A type of conversation that is tasteless, fruitless, unprofitable, trivial, and idle. It does good to no one, not even the one speaking. That temporary pleasure is like wormwood, bitter in the end. Foolish talking kindles no consolation, no bowels of mercy, strengthens no heart, or inspires no thought. It is not seasoned with the salt of grace.
There is, Paul says again, a filthy communication that should never come out of a Christian's mouth. It ministers to maliciousness. It points out what is evil and unholy. It covers over sin with happy, vivid, and enticing colors so that it might conceal its sinful acne. All such talk I must learn to hate. I must not listen to it in others nor tolerate it in myself.
Finally, there is, Paul says, a foolish jesting that is not becoming in the believer. I must be refined, tender-hearted, and affable in whatever humor I allow myself. There is humor, wit, banter, and sarcasm, which seem funny, yet are neither edifying nor kind. It is spoken in the service of sin and not in the service of Christ.
O LORD, set a watch over my lips so that I do not offend against Thee with my words. "A wholesome tongue is a tree of life!" My purest speech will need much distilling before it can join in the praises of Thy temple throng. For that eternal worship, I would tune my voice with the tones of prayer, the proclamation of the gospel, and the accents of Christ's redeeming love.