Nathan put forward a juicy difficulty for my position on lies in a comment. It runs:
"[God] also seems to either commend or participate in the deception of Israel's enemies, assuming the prophet in 1 Kings 22 is telling the truth, for example..."
Let me quickly break the passage down for you. Roughly summarised:
Ahab, king of Israel, consults his 400 non-Yhwh prophets to see if he should attack some cities. They say yes, you'll win. He gets advice to go a prophet of Yhwh, Micaiah (Mick to his mates). Ahab hates Mick because he's always prophesying that Ahab's going to cop it, but he asks him anyway.
Mick says, "Sure, go for it!"
Ahab says, "Yeah right, since when do you ever prophesy anything good for me?"
Mick says, "Yeah, just joking. You're going to get so smoten if you do. Also, I saw a vision where God told a spirit to tell all your dodgy prophets that you'd win, just so you'd go for it."
Then he tells everyone, "Mark my words, if he comes back alive from this battle, I'm not Yhwh's prophet."
Knowing the truth now, Ahab decides to have a crack anyway, but in disguise and with a stunt double. Short story shorter, the stunt double makes it out alive but Ahab cops an arrow to somewhere more vital than his knee.Now, there's lots to say about this passage about truth and lies. And lots of it, I think, mitigates the uncomfortableness of what God does in the sense that through this incident truth massively wins.
Despite this, the fact remains. God sent a spirit to deceive. God made Ahab believe something untrue. The thing that I think is most important to note is that God does so in judgement. Much, in fact, as God killed Ahab in judgement.
You see, what I'm getting at is that God's denial of the truth to someone, and even his giving them over to their delusions, (and given the nature of the prophets Ahab consulted this was definitely a product of Ahab's delusions) is destructive judgement. It was an act predicated upon his righteous decision as judge to finally destroy this wicked king after years and years of grace. In this case of deception, the only case of this exact nature I'm aware of in Scripture, it is synonymous with the bringing of death.
Now, Ahab actually knew what Yhwh had said before he went to battle. And Yhwh arranged that. So it's not as if God doesn't actually tell him what's in store if he fails to take heed. In fact, he makes sure the false information comes from the mouths of false prophets. The word from Yhwh's prophet came perfectly true.
But in reference to our current question of ethics, of what is right for humanity to do, the passage raises question marks. Is lying always wrong?
I would suggest that lying is in a similar category to killing. It almost never the right thing to do. I think that the kind and degree of reasoning that we ought apply before deceiving is of a similar order to that which we ought to apply before taking life. Partly because that's what lies end up doing. They destroy life.
God's purpose for this reality is life and thriving for people, and it is our duty to uphold this.
Yet, God reserves the right to destroy the destroyer. It's the kind of thing that God is free to utilise in judgement, but not so humanity. Not in the same way.