This devotional is about 2 Samuel 3.
David was a killer; a “man of blood” as some translations call him in 1 Chronicles 28:3. But look how horrified he was when Joab killled Abner here in 2 Samuel 3. He called on God to bring a perpetual curse on Joab’s family as a consequence of Joab’s sin (v. 29). He mourned the death of Abner, attending his funeral, crying for him, singing a lament for him (vv. 31-34), and fasting to demonstrate his mourning over Abner’s death (v. 35). Why would David, who killed so many people himself, be so horrified by the death of Abner?
The answer is that David’s killing was done in defense of his nation Israel. The Philistines, David’s most frequent opponent, were attacking Israel. Israel was not the aggressor in these situations; it was the victim of the aggression of its neighbors. While it is true that Israel attacked the nations living in Canaan, God made it clear that the command to attack them was not only to fulfill the Abrahamic covenant but also to punish these nations for their own sins (see Deut 9:5, 18:12). Just as God later used the Assyrians and Babylonians to judge Israel for her sins, he used the Israelites in the days of Joshua to punish the Canaanites for their sins. Having taken the land that God promised to them, Israel focused on settling and developing the promised land, not building an empire through never-ending attacks on other nations. War, and the killing that it requires, the killing that David did, was done in defense, not because David was a bloodthirsty man.
Our nation’s leaders should consider the ethics of war. American foreign policy in the past few decades has involved attacking other nations that have not attacked us. While this might seem like a smart idea tactically, it is not morally justified. It is, in fact, murder on a large scale. There is a time for “just war” but the just ones in any war are those who are seeking to defend their people and property. Human life is sacred, as David’s response to Abner’s death demonstrates. Since it is sacred, one should never attack another nation or person. Neither you nor I should ever take another person’s life unless that person has attacked us first with potentially deadly force. David’s response to Joab’s murderous attack on Abner shows that he understood the difference between defeating an enemy who has attacked you and getting revenge on someone through murder.
For much more on this, listen to a radio interview here that describes biblically what makes a just war: https://huffduffer.com/jonesay/345975