It's not just the humans in 2 Samuel who are big on loyalty. It's really important to God, too. Whereas betrayal seems bound to rebound back on the betrayer, loyalty pays major dividends. Even in cases where that loyalty doesn't seem to make cosmic sense—like, when David rewards people for dealing loyally with Saul's family—it seems to be a good thing.
Questions About Loyalty
If God doesn't care about Saul or his family anymore, why does it seem like a good thing for David to still deal loyally with Saul's family (except for the Gibeonite thing) and urge others to do so?
Is Abner loyal to Saul's family? Why does Ishbaal see Abner sleeping with Saul's former concubine as being a betrayal? Is Abner right to leave? Is Ishbaal the disloyal one?
Is Joab right when he says that David's sadness over Absalom amounts to a failure of loyalty towards the troops who fought to save David's life?
In his thanksgiving prayer, David says that God shows himself loyal to people who are loyal—is this statement universally true in 2 Samuel?