The major theme of 1 Samuel carries forward into all the historical books and is in fact a major theme of all the Scriptures: God honors those who honor Him and He dishonors those who dishonor Him. Not because He is obliged to act that way, but because He delights to be gracious to those who trust in Him and walk in His ways. Moreover God always holds people accountable who disregard Him and trash His will. And we see these principles, and others, exemplified repeatedly in 2 Samuel in the account of the reign of King David. As the Apostle Paul teaches us in Romans 15 and 1 Corinthians 10, all these things were written for our instruction in our own generation and to stimulate our perseverance in the faith. That is why we should never neglect these OT narratives. They are good for the soul.