14 Now the Spirit of the LORD had departed from Saul, and an evil spirit from the LORD tormented him.
15 Saul's attendants said to him, "See, an evil spirit from God is tormenting you. 16 Let our lord command his servants here to search for someone who can play the harp. He will play when the evil spirit from God comes upon you, and you will feel better."
I Samuel 16
This passage has me rather perplexed.
Here is some background...
Throughout Saul’s reign there were repeated battles against the Philistines and other peoples, including the Moabites, Ammonites, Edomites, and Amalekites. (1Sa 14:47, 48, 52) In the war against the Amalekites, Saul transgressed God’s command by sparing the best of their flock and herd as well as their king, Agag.
When asked why he had not obeyed God’s voice, Saul disclaimed guilt and shifted the blame onto the people. Only after Samuel emphasized the serious nature of the sin and said that, because of it, God was rejecting him as king did Saul acknowledge that his error was the result of his fearing the people. After Saul pleaded with Samuel to honor him in front of the older men and in front of Israel by accompanying him, Samuel did appear with him before them. Then Samuel himself proceeded to put Agag to death. After that, Samuel parted from Saul and they had no further association.—1Sa 15:1-35.
It was after this and after the anointing of David as Israel’s future king that God’s spirit left Saul. From then on “a bad spirit from God terrorized him.” Having withdrawn his spirit from Saul, God made it possible for a bad spirit to gain possession of him, depriving Saul of his peace of mind and stirring up his feelings, thoughts, and imaginations in a wrong way.
Saul’s failure to obey God indicated a bad inclination of mind and heart, against which God’s spirit offered Saul no protection or resistive force. However, since God had permitted the “bad spirit” to replace his spirit and terrorize Saul, it could be termed a “bad spirit from God,” so that Saul’s servants spoke of it as “God’s bad spirit.” On the recommendation of one of his attendants, Saul requested that David be his court musician to calm him when he was troubled by the “bad spirit.”—1Sa 16:14-23; 17:15.
In a nutshell, the bad spirit that deprived Saul of his peace of mind was the bad inclination of his own mind and heart—his inward urge to do wrong. When God withdrew his holy spirit, Saul lost its protection and came to be dominated by his own bad spirit. Since God permitted that spirit to replace His holy spirit, this bad spirit is termed “a bad spirit from God.” God did no terrorizing. It was all Saul's fault.
