Predestinated To Prosper

Why was Saul afraid of David? How did David act wisely? Why did Saul give his daughter to David 'as a snare to him'? Why do natural minded sinners [the flesh] revolt at the Gospel? Where did the adoption of the chosen sinners take place? Does God act or react to anyone but His Son? What is the difference between predestination and election? Are God's commands wishes of His? Is trusting a condition of predestination? Did David always behave wisely? Why did God take His hand off David at times and expose his depravity? How is Christ God's Elect?