"Set a watch, O Lord, before my mouth; keep the door of my lips." So wrote the Psalmist. He could not trust himself in this matter; and if idle words were to be disallowed an exit, the Lord must be the doorkeeper. "The tongue can no man tame," wrote the apostle as inspired by the Spirit of God (James 3:8). And again, "If any man offend not in word, the same is a perfect man" (James 3:2).
Perhaps we err more in this respect than in anything else. Let your speech be always with grace seasoned with salt. Prophetically it is written of Him who is our example as well as our Savior, "Grace is poured into Thy lips." "Never man spake like this Man." As the Man ever dependent and obedient, His ear was opened morning by morning to hear as the learned, that He should know how to speak a word in season to him that is weary (Isaiah 50). Hence "gracious words" seasoned with salt were spoken to men, insomuch that they marveled (Luke 4).
If we are to be well-pleasing to our Lord and Master either in public testimony or in ordinary conversation, we must be like Him in this respect, and as our lips are not holy naturally as His were, we need, like Isaiah, to have them touched by the live coal from off the altar. This seems to typify the teaching in Romans 6:11. If we are in the good of this, we shall be enabled to yield our members (including our tongue) as instruments of righteousness unto God (Romans 6:13). Love to one another would make us faithful to one another, speaking the truth in love, but in Revelation 2 and 3 we have in this respect a great pattern set before us; before a word of rebuke is uttered, the commendable things are taken notice of by Him whose eyes are as a flame of fire.
But out of the fullness of the heart the mouth speaks and no man’s words can be better than His thought, so we are exhorted to think on the things that are lovely, pure, and of good report (Philippians 4). The outcome of this thinking will surely be that we shall speak of these things, and if we see unlovely things in any of our brethren in Christ let us speak to the Lord about these rather than each other.