v5
And when Saul saw the host of the Philistines, he was afraid, and his heart greatly trembled.
I think that Saul would not have needed to be afraid, if he had just faithfully kept seeking the Lord, and not given up. At this point, I think that he still could have repented, and then things would not necessarily have turned out the way they did. He thought that he was doomed, and had no hope, and I think that became a self-fulfilling prophecy.
The lesson of Saul is not a lesson of the Lord dooming somebody to fail, no matter what he does. Saul still could have turned back to the Lord, all the way up to the end.
Application
When the work that I have to do seems to hard, and it seems like failure is inevitable, I'll just trust the Lord and keep faithfully serving Him and doing what is right, anyway. How do I know that, if I don't give up, something else isn't going on behind the scenes: like David and his mighty men, in the back with the enemy, ready to ambush and surround them, and deliver me?