[This is the first in a new series. Each week we're giving people at church the opportunity to ask questions about the sermon, about the Bible, or about life in general. We'll answer some of the questions once a month, and we'll try to answer all of the questions here. If you're a blog reader, feel free to post your question in the comments section.]
Basically, yes. Saul was jealous of David - insanely jealous - as in he was literally crazy at times. Because of Saul’s disobedience, God withdrew his blessing from Saul and put his blessing on David. David began to succeed more and more, and Saul became weaker and weaker. Apparently the event when Samuel anointed David as king was still mostly a secret, but everyone in Israel could see that David was becoming the national hero instead of Saul. Saul became increasingly jealous and afraid.
The really difficult part of this story is that multiple times 1 Samuel says God sent “a tormenting spirit” upon Saul, which sometimes sent Saul into depression and sometimes made him “rave like a madman.” Several times when this happened, Saul threw a spear at David - always just missing.
In chapter 19, the story takes a turn for the worse, and Saul began to pursue David with the army. That started a long drama of David running from Saul, yet remaining faithful and loyal to Saul all the while. Twice David could have killed Saul but didn’t. David only made a move to be king after Saul and Jonathan were dead. (See 1 Samuel 16-26.)