"Is Does not Mean Ought"

2 Samuel 3:27

So when Abner returned to Hebron, Joab took him aside into the middle of the gate to speak with him privately, and there he struck him in the belly so that he died on account of the blood of Asahel his brother.

A good example of how in the biblical narrative "is does not mean ought." Just because Joab treacherously kills Abner does not mean that God approved of his actions.  The writers of Scripture often write with the assumption that the reader will understand whether or not the character written about acted morally or not.  They write with the attitude "tell it like it is, warts and all."

I'm glad they wrote is way because it allows us to see human people with all of their flaws and how God works wi and through them to accomplish his purposes. Even when they do not believe in him.