One of the things that strikes me about Jonathan's friendship with David is how incredibly selfless it was.  Jonathan had every right to loathe David since he was the one who would be stealing the kingship from him.  But Jonathan understood God's higher purposes, and he knew that the leadership of the nation was being passed on to someone else.  Rather than fighting what he knew the Lord was doing, he decided to preserve his friendship with David and seek to defend the work of the Lord.  That says a lot about his character.  What do you do when you realize that God wants to raise someone else up instead of yourself?  Do you fight for what you believe should be rightfully yours?  Or do you submit, encourage, and even enable the process to go more smoothly?  In God's economy, personal glory has no value anyway… so if He wants to raise someone else up for a period of time, it's better to get out of the way.