Philistines worried

29 The Philistines gathered all their forces at Aphek, and Israel camped by the spring in Jezreel. ² As the Philistine rulers marched with their units of hundreds and thousands, David and his men were marching at the rear with Achish. ³ The commanders of the Philistines asked, “What about these Hebrews?”

Achish replied, “Is this not David, who was an officer of Saul king of Israel? He has already been with me for over a year, and from the day he left Saul until now, I have found no fault in him.”
⁴ But the Philistine commanders were angry with Achish and said, “Send the man back, that he may return to the place you assigned him. He must not go with us into battle, or he will turn against us during the fighting. How better could he regain his master’s favor than by taking the heads of our own men? ⁵ Isn’t this the David they sang about in their dances:

“‘Saul has slain his thousands,
    and David his tens of thousands’?”

⁶ So Achish called David and said to him, “As surely as the Lord lives, you have been reliable, and I would be pleased to have you serve with me in the army. From the day you came to me until today, I have found no fault in you, but the rulers don’t approve of you. ⁷ Now turn back and go in peace; do nothing to displease the Philistine rulers.”

The Philistines are blinded by their own pride and god. Israel has God, while they were against God. They worshipped idols and gods. Achish wanted David to follow the Philistines into battle, though the elders do not think thats a good idea! And they were right, David would kill them in the middle of battle. But they did not get the facts totally right. David would not kill for the glory of Saul, but for the audience of one, the almighty king, God. David's relationship with God was so deep that nothing can shake it. Not the Philistines and not Saul. He knows what He have to do, to kill God's enemies. Even though this was talking about a lot of killing and brutality. But today, we are spared from all that because Jesus Christ died for us and His blood covered for all our sins. All. If David have gone with the Philistines, i am sure that David would just kill all the Philistines there, without batting an eyelid.