Unlike 1&2 Corinthians, which are two separate letters written at different times about different topics to the same group of people, 1&2 Samuel was originally just one cohesive book which got chopped in two for reasons that are lost to history. The same holds true for the books of Kings and Chronicles. It's pretty clear that one of the major themes of Samuel is the contrast between the two men anointed by Samuel, at the command of God, to be king over Israel. One was chosen according to man's criteria, since Israel wanted a king to be like the nations. Really, the only description given of Saul in 1 Sam. 9 is that he was the most handsome man in Israel and he was the tallest man in Israel. In 10:24 Samuel asks the people, "Do you see him whom the LORD has chosen? There is none like him among all the people." But this man who looked the part did not have the courage, leadership, or moral character to be a good king, as his story shows us through the rest of 1 Samuel. Then there was the man whom God chose by His criteria, looking into his heart (1 Sam. 16:7). While David was far from perfect, his purpose in life was to serve God. When he needed to repent, he modeled for all future generations of believers what true repentance was. His reign was a golden age and became a symbol for the Messiah who was coming.
So, clearly, one of the themes of this book is the enormous difference between how man would choose versus how God chooses. In essence, it is a historical illustration of Isa. 55:9 "For as the heavens are higher than the earth, so are my ways higher than your ways and my thoughts than your thoughts."
Now, take that dichotomy, played out between two of God's anointed, and add to it the fact that nearly 28% of the times the words anoint and anointed are used in the OT, they are found in the book of Samuel. By page count in my Bible, Samuel is less than 7% of the OT. So, anointed is used four times as often as one might expect in this book. Now remember that Messiah just means The Anointed One. Could it be that Samuel was meant not just as an illustration of Is. 55:9, but as a reminder to the Jews during the time of Daniel's fourth kingdom (Rome, during which God would create His kingdom) that the Messiah might not look like they expected? Instead of an earthly, physical king ruling on a physical throne and ruling the world, Samuel reminds that God's plans might encompass more. It was to remind them that things are always better when we let God choose our kings, rather than when we choose them. Perhaps a study of this theme could help us convince Premillennialists of their errors. For me, the lesson is a reminder to let God choose and follow His plan. It is bound to be better than my meanderings.
Jer. 10:23 "I know, O LORD, that the way of man is not in himself, that it is not in man who walks to direct his steps."
Lucas Ward