" Like apples of gold in settings of silver Is a word spoken in right circumstances (Prov 25:11)."
"Speaking the truth in love, we are to grow up in all aspects into Him who is the head, even Christ (Eph 4:15)."
We grow up in all aspects not by merely speaking the truth, but by speaking the truth "in love." Without love, speaking the truth would be meaningless. As a matter in fact, Paul states that anything we may do is meaningless if it is without love (1 Cor 13:1-3). When we are speaking the truth in love, then we are truly using "sound words."
"If anyone advocates a different doctrine and does not agree with sound words, those of our Lord Jesus Christ, and with the doctrine conforming to godliness, he is conceited and understands nothing; but he has a morbid interest in controversial questions and disputes about words, out of which arise envy, strife, abusive language, evil suspicions, and constant friction between men of depraved mind and deprived of the truth ... (1 Tim 6:3-5)"
According to this passage, what are sound words? It involves the doctrine conforming to godliness. Paul then describes godliness by enumerating what it is not. Among other things, it does not involve abusive speech and constant friction. There were those who seemed to revel in friction, controversy, and abusive speech. Paul affirms that those who abuse, even if in the name of godliness, are depraved and understand nothing. A couple of proverbs add some more descriptions to these unsound people.
"A worthless man digs up evil, While his words are like scorching fire. A perverse man spreads strife, And a slanderer separates intimate friends (Prov 16:27-28)."
So, to add to the description of "depraved," they were also "worthless," and "perverse." Their words were like a scorching fire, an illustration James uses in James 3. Is it any wonder that God's instruction concerning those who abused with words was to "reprove them severely (Tit 1:13)?" Is it any wonder that Paul says to "Reject a factious man after a first and second warning (Tit 3:10)?"
The test for our words should consist of one simple question. Does it build up or tear down? That is what Paul is telling us in this final passage:
"Let no unwholesome word proceed from your mouth, but only such a word as is good for edification according to the need of the moment, so that it will give grace to those who hear (Eph 4:29)."