Everything the portrait of God’s character in the Bible is that of integrity, trustworthiness, and honesty God hates lying (Proverbs 12:22). Lying is a human trait, not a divine one (Romans 3:4). Liars deserve condemnation (Revelation 21:8). God is totally opposed to lying and stands completely against it as a means of achieving His will. How then does God approve of lying in this instance?
If the description of the scene here is taken as a stenographer’s record of the facts, then, God has made an exception to His general prohibition on lying. If the description is rather an explanation aimed at achieving a result with Ahab himself, then the account is a prophet’s depiction. God, portrayed as open to the use of lying, is given a “character” role in a story that does not reflect the real existence and character of God.
In any case, the endorsement God provides in this story is so exceptional that it cannot be taken as predictive of His normal operating procedure. God opposes lying, and God cannot oppose Himself.
2 CHRONICLES 18:21-22 – 21. And he said, I will go out, and be a lying spirit in the mouth of all his prophets. And the Lord said, Thou shalt entice him, and thou shalt also prevail: go out, and do even so.
22. Now therefore, behold, the Lord hath put a lying spirit in the mouth of these thy prophets, and the Lord hath spoken evil against thee.