In 2 Samuel 10 the Ammonites and Syrians are closing in on Israel. Joab divides up the men of Israel between himself and his brother, Abishai. He tells his strategy in v. 11, paraphrased, “You take those guys, I’ll take these guys, and let’s help one another if we need it.” That sounds simple enough. It’s the next line in v. 12 that is astounding. Joab declares:
Be of good courage, and let us be courageous for our people, and for the cities of our God, and may the LORD do what seems good to him.
Now we can read this and just chalk it up as another indication of Joab's super-manliness. We can picture him on the battlefield arrayed in armor and emanating more fierceness than Gerard Butler and Russell Crowe combined. But that would severely miss it.
Joab can say what he says because I think he knows what it is that “seems good to the LORD.” Remember the LORD’s promise to David in 2 Samuel 7? He told David, “Your house and your kingdom shall be made sure forever before me. Your throne shall be established forever” (7:16).
"What seems good to the LORD" is not “que sera, sera.” "What seems good to the LORD" is rooted in his unfailing faithfulness to fulfill his promises, whether Israel wins every single battle or not. "What seems good to the LORD" is that the house of David will be made sure forever and there will one day be a king on the throne of Israel whose reign will know no boundaries and have no end—King Jesus, the Christ.
I think that Joab knew this promise and that it was the real source of his courage. This is the kind of courage we need: not a blind fearlessness that comes from self-confidence, but a boldness that flows from being overcome by the reality of the gospel and the faithfulness of our God.
What doubts do you have concerning action for the sake of Christ’s Kingdom? What promise can you stand on and declare “may the LORD do what seems good to him”?