The people of God wanted a king. Not the King they had -- the one who rescued them out of slavery from Egypt, the one who brought them safely through the sea and the wilderness, the one who time and time again protected them from their enemies and brought them into a good land he promised to them. No, they wanted a human king to be like all the other nations. The person they saw fit to be king was much different than what God saw they needed, and eventually, God would show them how to look for the true king. What is it we're looking for?
Appointing A King
God's people wanted a king, just like the other nations had. They wanted one who would represent them well. One who was tall, handsome, strong - a natural leader.
But God was their true King, and if He was going to give them a human representative it would be one who represented what He is like - not what the other nations were like. This is the context where we find the power struggle between Saul and David.