Desperation

In 1 Samuel 21-22, Saul and David are both desperate men. But not in the same way.

Saul is desperate to hang on to his kingdom, his throne. He has been king over Israel and has seen some victories, yet he feels conspired against by his own son and one of his captains. He hears the song his subjects sing, attributing greater success to this captain than to him. He believes all is against him. He sees his kingdom slipping away. He mutters, spear in hand, vowing to strike this captain down.

David is desperate, running for his life, hungry, with not even a sword to protect himself. His only friend has done all he can to help. He is so afraid that, in his mind, Gath, Goliath's home is safer than Jerusalem. The Philistine hometown of his most famous conquest seems more welcoming to him than his assigned post. Treachery is all that awaits him at home.

David is the captain that Saul fears.

Saul is desperate because the kingdom has been torn from him and given to David. David is desperate because Saul is nurturing the idea of murdering David over the kingdom. In their desperate hours, David looks to God, to "know what He will do for me". 

Saul, clinging to his spear, perhaps the only thing he has managed to hold, looks inward saying, "none of you is sorry for me".

Desperation drives David to God and drives Saul to despair.