It is a Kingdom Issue
Chapter 22 of 1 Samuel, leads us to Saul taking a turn for the worse. He fears that his own people are out to get him. He thinks that everyone is siding with David and in turn, is filled with a tremendous amount of hate and jealousy towards David and his "so-called" followers. So much so that Saul decides to completely destroy everyone and everything that he thought was against him. The bottom line is that Saul had a heart problem. Saul only served Saul. He is happy enough to appear to serve God as long as it doesn't cost him anything. If our kingdom, our passion, our commitment is to the things of this life, then our allegiance is to the world and not God. Our kingdom is ourselves in this scenario. We should be seeking the Kingdom of God first!