Success in Battle
Saul was commanded by God to go and kill Amalek and everything he had, including all the animals (1 Samuel 15:3). Saul gathered an army together and set up an ambush in the city of Amalek (15:4, 5). Saul defeated the Amalekites, but there was a problem. Disobedience
"Saul and his people spared Agag (king of the Amalekites) and the best of the sheep, the oxen, the fatlings, the lambs, and all that was good, and were not willing to destroy them utterly; but everything despised and worthless, that they utterly destroyed" (15:9).
Regret
Because Saul had disobeyed, God regretted making him King. The Lord said to Samuel, "I reget that I have made Saul king, for he has turned back from following Me and has not carried out My commands" (15:11). We then see Saul lie to Samuel by telling him that he has carried out the commandments of the Lord (15:13). Samuel asked him what the bleating of the sheep was he heard. Saul tried to blame the people for taking the animals in Amalek. Samuel said "The Lord sent you on a mission and said, Go and utterly destroy the sinners, the Amalekites, and fight against them until they are exterminated. Why then did you not obey the voice of the Lord, but rushed upon the spoil and did what was evil in the sight of the Lord" (15:18, 19).
The Outcome
Samuel said, "For rebellion is as the sin of divination, and insubordination is as iniquity and idolatry. Because you have rejected the word of the Lord, He has also rejected you from being king" (15:23).
What we can learn
It seemed so harmless didn't it. After all Saul carried out what he was told. He went in and destroyed most everything. In fact he did destroy everything that was bad. Saul tried to make this argument in verse 20. He told Samuel "I did obey the voice of God." It appears in his mind because he did most everything God said that he was obeying God. We do this today. Many of us may believe that because we do most everything God says, we are in a right relationship with Him. We are horribly mistaking if we believe this. We must not take portions of God's word and leave the rest. We must do all that God has laid in His word for us to follow.
The results of Disobedience
The results are simple. If we do most but not all we are told, we may be like Saul. Because he kept some of the spoil he was told not to, God rejected him as king. He didn't follow the commands of God fully. If we don't follow the commands of God fully, God may reject us on the day of judgment. I encourage you to study God's commandment in His holy word. When Jesus returns we don't want to be thinking we have done all that we were commanded but then realize we have only done part of what was commanded. Study the word!
