Joab is probably not anyone's favorite character in the Old Testament; he certainly isn't mine. This commander of King David's armies is often a jerk, likes to take matters into his own hands for his own reasons, even when it is potentially disastrous, and has even been known to obey such wicked orders as, "Set Uriah in the forefront of the hardest fighting, and then draw back from him, that he may be struck down, and die" (2 Samuel 11:15). And yet, there are some points in the story of David's reign where this too-violent Joab speaks as though he were the one who was the "man after God's own heart". It is Joab who rebukes David for mourning over the death of his wicked son, Absalom, to the shame of all of those who fought valiantly against the usurper (2 Samuel 19:5-7). It is also Joab who sternly warns David against taking an ungodly census of the Israelites in 2 Samuel 24 that would end up killing thousands.
But one of my favorite lines from the lips of Joab comes in 2 Samuel 10:12. As he is organizing the placement of his troops in a battle against the joined forces of the Ammonites and Syrians, he says to his brother, Abishai, "Be of good courage, and let us be courageous for our people, and for the cities of our God, and may Yahweh do what seems good to Him."
I love that that statement for two reasons. First, it acknowledges God's sovereignty and the fact that He "works all things according to the counsel of His will" (Ephesians 1:11). It is as Job stated, once he had been duly corrected by God, "I know that you can do all things, and that no purpose of yours can be thwarted" (Job 42:2). Joab's wise sentiment is rooted in an understanding that God is truly on the throne of all His creation and that He has plan - a will - that He will not fail to work out. Joab also knows that no human action can constrain that will of God. In other words, we can't force Him to side with us or do for us exactly what we would like Him to do. He will always "do what seems good to Him."
The second reason that I love Joab's statement to his brother is because it shows us the wondrous simplicity of our responsibility as human beings. Notice that he doesn't tell his brother anything like, "Make sure you rout their western flank, or the battle will be lost!" He understands - quite differently from almost everyone in our own day - that the victor in a battle is determined by Yahweh. God can defeat a huge host of warriors at the hands of one man and his armor bearer, as He did in 1 Samuel 14. He can also engineer events so that an army that is vastly successful one day gets hammered the next, as He did in the issue of Achan's sin at Ai in Joshua 7. So what matters is not individual strategies or even the military skill and might of champion warriors. What matters is what God wants to do. And the most important thing that we can do in light of that fact is just simply to make sure that we are being the kind of people that God has commanded us to be.
One church sign that I saw on the way to work one morning put it like this: "Obey God's commands and let Him take care of the rest." And that's it in a nutshell! You and I are not the ones on the throne; we are the ones that should be on our knees in front of the throne. Therefore, our place is not to dictate the events of history - whether that means thinking that we should be able to accomplish whatever we desire by our own hard efforts, or whether that means thinking that God has to answer our prayers in a certain way. Instead, our role in all of these things is blessedly simple: just obey the King!
Obedience is very important to God. And it is very important in the New Testament context of the church as well. Some of Jesus' last and most important words on earth to His disciples, before ascending to heaven, were "...and teach them to obey all that I have commanded you" (Matthew 28:20). Our God has not made His commands hard to find or ambiguous. The Scriptures are full of His laws and statutes and rules and instructions. They are "more to be desired than gold, even much fine gold; sweeter also than honey and the drippings of the honeycomb" (Psalm 19:10). And here is the wonderful, freeing, most basic truth of a life of faith: just concern yourself with obeying your awesome God, and "let Him do what seems good to Him."