What is the theme in A Tale of Three Kings by Gene Edwards?

Being a David is another theme in the book. David is a kind young man who works hard and tries to always do the right thing. When David is very young he is visited by an old king who tells him he will one day be a great king himself. David does not let this go to his head, but continues to live his life as though he has never heard this prophesy. David practices throwing rocks while watch his father's sheep and one day this skill comes to his rescue when he must save a sheep from a bear. Later David will use the skill again against a great giant, causing himself an embarrassing reputation. When David is older, he goes to live with King Saul in order to learn from the great king. Saul is jealous of David and afraid of losing his kingdom to the younger man, so he treats him unkindly.