The lips of the righteous know what is fitting, but the mouth of the wicked only what is perverse. Proverbs 10:32.
The last five verses of Proverbs 10 teach values accruing from righteousness. The word “righteousness” is not in everyday use, so we need to know what it means. The common idea that it means goodness, or just “being good,” falls well short of the mark; it provides no standard to measure goodness.
A previous verse, 27, helps clarify the meaning: “The fear of the LORD adds length to life.” “Fear” in this sense is not terror, as some might interpret it, but respect for God. Thus, the righteousness that produces joy, safety, stability, and wisdom denoted in verses 28–31, is abiding in God’s counsel.
Unfortunately, our human thoughts and words are distorted by our sinful nature, which undermines the wisdom we devise. Thus, our words may be either fitting or perverse. Only as our thoughts are “transformed by the renewing of [our] mind,” will we “be able to test and approve what God's will is . . .” Romans 12:2.
But the renewing of our mind is not simply an educational process. The more we consider we have mastered the Word, the more likely we are to pervert it with our own ideas. For our words to be fitting, we prayerfully need to gain God’s ideas embedded in His Word, not just a mechanical exposition of the text.