Problem: According to this passage, the evil (“distressing,” nkjv) spirit came upon Saul so that he prophesied in his house, and then tried to kill David with a spear. However, the verse clearly states that the evil spirit was from God. How could a good God send an evil spirit to bring distress to Saul?
Solution: Because God is absolutely sovereign, the actions of any evil spirit would be subject to the authority of God. Therefore, it was according to God’s permission that the spirit was allowed to come upon Saul to bring him distress. Saul had already rejected God, and God had rejected him from being king. God had a special reason for allowing this spirit to incite Saul to action against David. Saul’s attempt to kill David only made Saul realize that God was with David. By sending David away and making him captain over a thousand, Saul inadvertently increased David’s popularity with the people and hastened his own demise. The sending of the evil spirit upon Saul is similar to God’s allowing Satan to afflict Job. God allows evil, but always uses it to accomplish His own good purposes (see comments on 1 Kings 22:22).