In order to be safe from Saul, David goes to live among the Philistines, the enemies of Israel. David conducts raids against other enemies of Israel from his Philistine base, but tells the Philistines he has been attacking Israel so the Philistines will trust him and allow him to stay.
This has to have been a terrible life for David and his men. He is God’s chosen king, but is living as a refugee. We live as refugees as well. We are part of God’s family, but living here on earth among those who are God’s enemies. God will make things right in the future, but for today we need to endure hardship.