The Spirit of the Lord comes upon David and leaves Saul, and an evil spirit comes and distresses him. This was due to Saul's resistence to the the Holy Spirit, he had spent so long rebelling against the Spirit of the Lord that he no longer wanted to have the Spirit so He left him, and the vacuum was filled by an evil spirit which Saul wanted as was shown by his actions. The servants of Saul knew what had happened to him and asked if they should bring someone to worship the Lord before the king and lift his mood. So they went out and found David who was a skillful player of the harp and was already described as a man of war both in the sphere of physical and spiritual warfare. Pastor Guzik tells of how worship is indeed a battleground, and espescially music as it is so powerful in speaking to our inner man either for good or for evil.
