1 Samuel 18:1-16
As soon as he had finished speaking to Saul, the soul of Jonathan was knit to the soul of David, and Jonathan loved him as his own soul.  And Saul took him that day and would not let him return to his father's house.  Then Jonathan made a covenant with David, because he loved him as his own soul.  And Jonathan stripped himself of the robe that was on him and gave it to David, and his armor, and even his sword and his bow and his belt.  And David went out and was successful wherever Saul sent him, so that Saul set him over the men of war. And this was good in the sight of all the people and also in the sight of Saul's servants.
Saul's Jealousy of David
 As they were coming home, when David returned from striking down the Philistine, the women came out of all the cities of Israel, singing and dancing, to meet King Saul, with tambourines, with songs of joy, and with musical instruments.  And the women sang to one another as they celebrated,
“Saul has struck down his thousands,
and David his ten thousands.”
 And Saul was very angry, and this saying displeased him. He said, “They have ascribed to David ten thousands, and to me they have ascribed thousands, and what more can he have but the kingdom?”  And Saul eyed David from that day on...[read full text]...
This list contains some of the resources that were used to prepare this sermon. Check them out if you want to dig a little deeper.
Harvard Business Review
, "Envy at Work
," by Tanya Menon and Leigh Thompson.
The Great Divorce
, C.S. Lewis
Ray Cortese, "Envy