If you missed part 1, check it out here.
Saul was just anointed king. His first order of business is to stand up to their bullies, the Philistines who had been oppressing Israel. The Philistines had a huge army. Saul was waiting for Samuel. Israel was basically hiding in rocks, and they started losing some troops. The FOMO (Fear Of Missing Out) Saul started to feel caused him to be moved by fear instead of being moved by the direction of the Lord.
12 So I said, ‘The Philistines are ready to march against us at Gilgal, and I haven’t even asked for the Lord’s help!’ So I felt compelled to offer the burnt offering myself before you came.” 13 “How foolish!” Samuel exclaimed. “You have not kept the command the Lord your God gave you. Had you kept it, the Lord would have established your kingdom over Israel forever. 14 But now your kingdom must end, for the Lord has sought out a man after his own heart. The Lord has already appointed him to be the leader of his people, because you have not kept the Lord’s command.”1 Samuel 13:12-14 NLT