Power corrupts and absolute power corrupts absolutely.
Per CM, Saul had everything in his favor:
1) a strong body, 10:23; Saul was taller than any of the people.
2) a humble mind, 9:21; Saul questioned why he was closen as he was a from the small Benjamin tribe of Israel.
3) a new heart, 10:9; God gave him another heart and patience to wait seven days to be called by Samual.
4) spiritual power, 10:10; “the Spirit of God came upon him, and he prophesied among them.”
5) loyal friends, 10:26; Saul had with him a band of men, “whose hearts God had touched.”
6) Saul had the guidance and prayers of Samuel.
1) It took the young David to slay the mighty Goliath.
2) Saul became very proud and was obsessed with jealousy towards David and tried to kill him.
3) 1 Samuel 13:8, “And he tarried seven days, according to the set time that Samuel had appointed: but Samuel came not to Gilgal; and the people were scattered from him.” Saul became impatience and he offered the burnt offering. This was a serious transgression as Saul was acting as both priest and King. There were only two men who were both priest and King, Jesus, and Melchizedek king of Salem. Someday we, the Church, will also be priests and Kings.
5) Saul was losing any grip on reality and ordered the priests he accused of helping David killed. His guards refused so “Doeg the Edomite turned, and he fell upon the priests, and slew on that day fourscore and five persons that did wear a linen ephod.” The deaths of 85 priests didn’t satisfy Saul and he also attacked Nob, Ahimelech's city, and killed all the inhabitants and livestock.
4) & 6) Saul disobeyed the commandment by God to destroy the Amalekites but spared their king Agag. Samuel quickly dispatched the king. 1 Samuel 15:35, “And Samuel came no more to see Saul until the day of his death: nevertheless Samuel mourned for Saul: and the LORD repented that he had made Saul king over Israel.”
Later Saul was facing battle and wanted council from the dead Samuel. Saul had the witch of En-dor conjure Samuel, a very major transgression against God's commend. 1 Samuel 28:19, "Moreover the LORD will also deliver Israel with thee into the hand of the Philistines: and tomorrow shalt thou and thy sons be with me: the LORD also shall deliver the host of Israel into the hand of the Philistines." The next day Saul and his sons were dead.
The early promise of Saul and his fall from grace demonstrates what pride, arrogance, impatience, not taking council, and breaking God’s laws can do. Better to remember the words of Micah 6:8, “He hath shewed thee, O man, what is good; and what doth the LORD require of thee, but to do justly, and to love mercy, and to walk humbly with thy God?”