The wise man who has knowledge lives according to the truth through a totally honest life. Honesty means first of all, to speak the truth and never to. “bear false witness.” (Exodus 20:16)
There are six things which the Lord hates, seven which are an abomination to Him: haughty eyes, a lying tongue and hands that shed innocent blood, a heart that devises wicked plans, feet that make haste to run to do evil, a false witness who breathes out lies, and a man who sows discord among brothers. (Proverbs 6:16-19; Cf 11:1, 12:17, 17:4, 21:28, 25:14, 18)
This basic scriptural teaching is also that of the apostles.
For we pray to God that you may not do what is wrong…but that you may do what is honest…for we cannot do anything against the truth, but only for the truth. (2 Corinthians 13:7-8)
Honesty also means to act truly and openly, without pretense, or the presentation of a false image of oneself. It means, in a word, not to be a hypocrite.
Above all things, Christ the Lord hated and condemned hypocrisy, lying and deceit. He accused the devil himself, first and foremost, of being a deceiver and liar, pretending to be other than he is, presenting himself and his teaching as totally other than the falsehood and wickedness that they actually are. (Cf. John 8:44-47) This is the way of all the false prophets, and of the antichrist himself.
For many deceivers have gone out into the world, men who will not acknowledge the coming of Jesus Christ in the flesh; such a one is the deceiver and the antichrist. (2 John 7)
Take heed that no one leads you astray. For many will come in my name saying “I am the Christ,” and they will lead you astray. (...)and many false prophets will arise and lead many astray. (...) For false Christs and false prophets will arise and show great signs and wonders, so as to lead astray, if possible, even the elect. (Matthew 24:4,11,24)
In His fierce condemnation of the evil of the scribes, pharisees and lawyers, Christ was most violent against their hypocrisy. Of all the evils of men, the most vile in the sight of the Lord is undoubtedly hypocrisy.
Woe to you, scribes and Pharisees, hypocrites! for you cleanse the outside of the cup and the plate, but inside you are full of extortion and rapacity. You blind Pharisee! first cleanse the in- side of the cup and the plate, that the outside also may be clean.
Woe to you, scribes and Pharisees, hypocrites! for you are like whitewashed tombs, which outwardly appear beautiful, but within are full of dead men’s bones and all impurity. So you also outwardly appear righteous to men, but within are full of hypocrisy and iniquity. (Matthew 23: 25-28)
The spiritual person is not a hypocrite. He shows himself honestly for what he is, and does not pretend to be what he is not. He reveals himself to all exactly as he actually is. He does not say or do anything that would lead people to have a false impression of him or of anyone or anything. He is utterly honest and pure in all that he things, says and does, knowing that God sees all and judges with righteousness all those who “walk in integrity.” (Cf. Psalm 26:1,11)