"Thou shalt not bear false witness against thy neighbour." (Exodus 20:16)
There are several important and very specific words used in this commandment. An expanded translation could well be, "Do not purposely intend to injure or plan to deceive others by repeating a damaging report about one with whom you have established a relationship."
The very idea of a lie originated with the great enemy, Satan (John 8:44; 1 John 2:21), no doubt rendering the lying tongue an abomination to God (Proverbs 6:17-19; 12:22).
The willing false witness will not escape punishment (Proverbs 19:5, 9). Indeed, such a person may die prematurely (Acts 5:4-10).
Untruth is not overlooked by God. In fact, those who are "liars" by practice will likely wind up in hell (Revelation 21:8, 27; 22:15).
While the focus of this commandment prohibits a "formal" false witness against someone--which would result in damage to their person, property, or reputation--the biblical applications are many and varied. Our holy God hates a false witness.
So-called "half truths" are not godly, either. Flattery and hypocrisy are wrong (Psalm 12:1-3; Proverbs 29:5), as are malicious joking and jesting (Proverbs 26:18-19; Ephesians 5:4). Even deceptive refusals are considered ungodly behavior (Proverbs 3:27-29; 1 John 3:17-18). And, of course, slander, gossip, and "tale bearing" are wrong (Psalm 101:5).
Those who name the name of Jesus Christ are, simply, to speak the truth (Ephesians 4:25), render sound judgment (1 Corinthians 6:1-5), and not to enter into a plot to do evil (Zechariah 7:9-10; Romans 12:9, 17, 21). Our "yes" and our "no" are to be precise and accurate (James 5:12). HMM III