Firstly I would say that there are some passages of Scripture that may appear to favour 1 view over another. If this is the case then much consideration should be given to that view. However Scripture is a unified whole, and an alternative interpretation of a passage that is both valid and more in line with other Scripture is to be preferred.
The passages Michael mentions are:
And God sent an evil spirit between Abimelech and the leaders of Shechem, and the leaders of Shechem dealt treacherously with Abimelech, (Judges 9)
Now the Spirit of the LORD departed from Saul, and a harmful spirit from the LORD tormented him. And Saul's servants said to him, "Behold now, a harmful spirit from God is tormenting you. Let our lord now command your servants who are before you to seek out a man who is skillful in playing the lyre, and when the harmful spirit from God is upon you, he will play it, and you will be well." (1 Samuel 16)
And Micaiah said, "Therefore hear the word of the LORD: I saw the LORD sitting on his throne, and all the host of heaven standing beside him on his right hand and on his left; and the LORD said, 'Who will entice Ahab, that he may go up and fall at Ramoth-gilead?' And one said one thing, and another said another. Then a spirit came forward and stood before the LORD, saying, 'I will entice him.' And the LORD said to him, 'By what means?' And he said, 'I will go out, and will be a lying spirit in the mouth of all his prophets.' And he said, 'You are to entice him, and you shall succeed; go out and do so.' Now therefore behold, the LORD has put a lying spirit in the mouth of all these your prophets; the LORD has declared disaster for you." (1 Kings 22)Michael could have also suggested this verse,
I form the light, and create darkness: I make peace, and create evil: I the LORD do all these things. (Isaiah 45 KJV)There are at least 3 issues that are relevant here.
The first is that God is able to use wicked men (or wicked beings) for his own purposes. Abimelech and the leaders of Shechem were both deceptive. They had made wicked choices. That God allows or even sends an evil spirit to them is not saying that God willed the spirit reject him in the earlier celestial rebellion. There is no indication that demons are able to be redeemed but that does not prevent God from using them in his dealings with men. Similar could be said for the situations involving Saul and Zedekiah (whom Micaiah rebuked).
The second issue is that Scripture attributes to God things that he allows (presumably when they accord with his desires) even if the instigator is other than God. Because God has the power to do or prevent anything he is rightly seen as sovereign. This means that we can appeal to God in our situation. We can ask God why we are in some situation even if God did not cause the situation. This is because God has the power to prevent it. This does not necessarily make our appeal valid, but we can make this appeal. Satan oppressed Job, but could only do so with God's permission, and Job's response to his wife was,
"Shall we receive good from God, and shall we not receive evil?" (Job 2)Likewise when David held a census of Israel. 1 Chronicles attributes this to Satan but 2 Samuel mentions that God intended on judging Israel for their sin. Satan has intentions for evil against the nation of Israel just as he had against Job. In this situation it suited the purposes God otherwise had—judgment on Israel—and thus God allowed Satan to act out Satan's intentions.
Thus far the assumption is that the evil spirit in these passages was an unclean spirit, ie. demon. This is the case with Satan and a case could be made for the evil and lying spirits in the 3 passages Michael quoted. This, however, is not a given, which leads us to the third issue: what does "evil" mean?
In the Judges passage "evil" is the word ra' (07451), as is the word "harmful" in the Samuel passage. Lying is sheqer (08267) in the Kings passage. "Evil" in Isaiah and Job above is also the word ra'.
The problem with the word "evil" is that as an English word it has moral connotations. "Evil" means a negative event though we also associate "evil" with causation by a wicked agent. Compare the word "bad" in English which means a negative event but may not necessarily imply anything about the cause. Here are the definitions of ra' when used as an adjective:
1) bad, evil
1a) bad, disagreeable, malignant
1b) bad, unpleasant, evil (giving pain, unhappiness, misery)
1c) evil, displeasing
1d) bad (of its kind - land, water, etc)
1e) bad (of value)
1f) worse than, worst (comparison)
1g) sad, unhappy
1h) evil (hurtful)
1i) bad, unkind (vicious in disposition)
1j) bad, evil, wicked (ethically)
1j1) in general, of persons, of thoughts
1j2) deeds, actions
So the question is what ra' both means and implies in Hebrew. It can mean wickedness (1j above). Does it usually imply immoral causation? How much of its meaning is contextual compared to intrinsic? Note, for example, that the translation of Isaiah I quoted was the King James Version. Modern versions, including the literal New American Standard, use the term "disaster". The modern versions give the word a negative meaning without the associated implication of a wicked agent.
I don't know Hebrew to judge the appropriateness of this translation and I am reliant on translators. We do know that it is largely context that determines meaning. It is also likely that the Hebrews (at least during some stages in history) were okay with figurative and hyperbolic language; more so it seems than modern Westerners. Compare Rachel was loved but Leah hated, ie. less loved compared to Rachel (Genesis 29).
This could mean that the phrase "evil spirit" was not giving us information on whether we are dealing with the angelic or demonic. Rather the descriptor "evil" concerns the mission of the spirit: one causes confusion or harm. The New English Translation opts for this translation in the Judges passage:
God sent a spirit to stir up hostility between Abimelech and the leaders of Shechem. He made the leaders of Shechem disloyal to Abimelech. (Judges 9)Is it possible that the phrase "lying spirit" is a similar example? A spirit that deceives those who have rejected the truth; compare 2 Thessalonians 2.