The Amalekites had done something horrifically and grievously evil to God.  When the Israelites had left Egypt and were peacefully traveling through, the Amalekites picked off the slower ones–the old, the sick, the children.  If you want to make God furious and come to know his wrath, bring harm to the vulnerable and defenseless, especially when they are His own people.

Remember what the Amalekites did to you along the way when you came out of Egypt.  When you were weary and worn out, they met you on your journey and attacked all who were lagging behind; they had no fear of God. When the Lord your God gives you rest from all the enemies around you in the land he is giving you to possess as an inheritance, you shall blot out the name of Amalek from under heaven. Do not forget!  (Deut 25:17-19).

Now they were settled in the land.  God spoke to Saul and told him to go to war with the Amalekites and completely destroy them for what they had done to the Egyptians.  It was His justice against them for what they done to the Israelites.

So Saul gathered the armies and went to war against the Amalekites.  He captured their king and destroyed their armies in battle.  BUT….he saved the animals and best of everything for himself.

When Samuel came and confronted him for his lack of full obedience, Saul said he did it “for the Lord.”  It’s here that Samuel makes a powerful statement (1 Sam 15:22-23):

But Samuel replied:

“Does the Lord delight in burnt offerings and sacrifices
as much as in obeying the Lord?
To obey is better than sacrifice,
and to heed is better than the fat of rams.
For rebellion is like the sin of divination,
and arrogance like the evil of idolatry.
Because you have rejected the word of the Lord,
he has rejected you as king.”

We can’t disobey the Lord for the sake of doing something “for the Lord.”  It doesn’t work that way.  But in this confrontation, the truth of Saul’s heart came out.

I have sinned.  I have transgressed the LORD’s command and your words.  Because I was afraid of the people, I obeyed them” (2 Sam 15:24).

It’s a dangerous thing when a leader of the people puts his fear of the people before his fear of God.  And Saul did just that.  The people were putting extreme pressure on him and he succumbed and justified his decision.  It cost him his rulership.  And God regretted that he made Saul king.  Tough words.  An important lesson for all because we are all leaders in some way or another.