What a strange picture in this short story. David, the fearless Israelite who had fought against Goliath and the Philistines, is now going out with the Philistines to battle against Israel! Always remember that God did not write the Bible to exalt any man or woman, but to show His own perfection and glory. Every person fails. But also never forget that when we have accepted Christ as our Savior, we have been made as perfect as He is (Heb. 10:1414For by one offering he hath perfected for ever them that are sanctified. (Hebrews 10:14)). We have received Eternal Life (1 John 5:1111He answered them, He that made me whole, the same said unto me, Take up thy bed, and walk. (John 5:11)). Do not confuse our perfect, holy position before God in Christ, with the old life. When we do what we want we are going back to that old life. We only sin because we want to (Read Rom. 8:22For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death. (Romans 8:2)). They go on side by side. On the first, Scripture says He hath perfected forever them that are sanctified, all believers (Heb. 10:1414For by one offering he hath perfected for ever them that are sanctified. (Hebrews 10:14)), and Paul said “In me, that is in my flesh dwells no good thing” (Rom. 7:1818For I know that in me (that is, in my flesh,) dwelleth no good thing: for to will is present with me; but how to perform that which is good I find not. (Romans 7:18)).
V.7-8 Even when David is told that he is in the wrong place, he argues that he wants to stay. But the Lord was over all this, and He will not allow David to go out to fight against Israel.