In 1 Samuel 18 & 19 we see how insecurity and jealousy blurred Saul’s vision.
David had done nothing but good for Saul. Jonathan spelled this out when talking to his father Saul in ch 19 verse 5. David had been a model of virtue and courage. Saul should have loved him, been so grateful to him. But instead Saul viewed him as his enemy ( Ch 19 verse 17).
David being Saul’s enemy had nothing to do with how David had behaved. His behaviour called for the opposite response, he should have been Saul’s hero, Saul’s friend. It had everything to do with the state of Saul’s heart. What he had allowed into his heart, insecurity leading to anger and jealousy ( Ch 18 verse 8 & 12 ). These were blurring Saul’s vision horribly. David his friend he saw as his enemy.
We must guard our hearts from insecurity and all that it gives rise to, anger, jealousy etc…..because like Saul we will see friends as enemies, it will blur our vision.