Obedience is better than sacrifice. I'm sure all of us have heard of this phrase before. God has commanded Saul to destroy everything when attacking the Amalekites and when God says 'everything', he meant literally 'everything'. Saul & his army however were unwilling to destroy everything, they destroy the weak but took the best. It was totally wrong for Saul to think either that the Lord wouldn't know or by sacrificing those things to God, what he had done would be justified.