He shall judge between the nations,
and shall decide disputes for many peoples;
and they shall beat their swords into plowshares,
and their spears into pruning hooks;
nation shall not lift up sword against nation,
neither shall they learn war anymore.
But before New Jerusalem is established there must be war. We are fighting it now. Joel 3:9-10 reads,
Proclaim this among the nations:
Consecrate for war;
stir up the mighty men.
Let all the men of war draw near;
let them come up.
10 Beat your plowshares into swords,
and your pruning hooks into spears;
let the weak say, “I am a warrior.”
David was a man after God’s own heart and he was a warrior king. It was necessary for him to lead the army and fight and defeat Israel’s enemies. 2 Samuel 8 records his military might. Verses 1-8 read,
After this David defeated the Philistines and subdued them, and David took Metheg-ammah out of the hand of the Philistines.
2 And he defeated Moab and he measured them with a line, making them lie down on the ground. Two lines he measured to be put to death, and one full line to be spared. And the Moabites became servants to David and brought tribute.
3 David also defeated Hadadezer the son of Rehob, king of Zobah, as he went to restore his power at the river Euphrates. 4 And David took from him 1,700 horsemen, and 20,000 foot soldiers. And David hamstrung all the chariot horses but left enough for 100 chariots. 5 And when the Syrians of Damascus came to help Hadadezer king of Zobah, David struck down 22,000 men of the Syrians.6 Then David put garrisons in Aram of Damascus, and the Syrians became servants to David and brought tribute. And the Lord gave victory to David wherever he went. 7 And David took the shields of gold that were carried by the servants of Hadadezer and brought them to Jerusalem. 8 And from Betah and from Berothai, cities of Hadadezer, King David took very much bronze.
God used David, his warrior king to conquer the surrounding nations, to build Israel’s wealth, to build David’s reputation and spread His glory to the nations. David was as Jesus is a warrior king. God’s name LORD of Hosts means He leads the angel armies. The angel armies are not meek, weak, or gentle. They are fierce, they are the instruments of God’s wrath, and the bringers of God’s justice. Revelation 19:11-16 describes Jesus as the LORD God of Hosts, the Warrior King.
Then I saw heaven opened, and behold, a white horse! The one sitting on it is called Faithful and True, and in righteousness he judges and makes war. 12 His eyes are like a flame of fire, and on his head are many diadems, and he has a name written that no one knows but himself. 13 He is clothed in a robe dipped in blood, and the name by which he is called is The Word of God. 14 And the armies of heaven, arrayed in fine linen, white and pure, were following him on white horses. 15 From his mouth comes a sharp sword with which to strike down the nations, and he will rule them with a rod of iron. He will tread the winepress of the fury of the wrath of God the Almighty. 16 On his robe and on his thigh he has a name written, King of kings and Lord of lords.
We will have eternal peace one day, but now we are in a war and we are expected to do our part. Paul describes it in Ephesians 6:10-20
Finally, be strong in the Lord and in the strength of his might. 11 Put on the whole armor of God, that you may be able to stand against the schemes of the devil. 12 For we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places. 13 Therefore take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand firm. 14 Stand therefore, having fastened on the belt of truth, and having put on the breastplate of righteousness, 15 and, as shoes for your feet, having put on the readiness given by the gospel of peace. 16 In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one; 17 and take the helmet of salvation, and the sword of the Spirit, which is the word of God, 18 praying at all times in the Spirit, with all prayer and supplication. To that end keep alert with all perseverance, making supplication for all the saints, 19 and also for me, that words may be given to me in opening my mouth boldly to proclaim the mystery of the gospel, 20 for which I am an ambassador in chains, that I may declare it boldly, as I ought to speak.
This war is not a normal war where earthly armor would do. Like earthly armor impeded David in order to fight Goliath (1 Samuel 17:38-40) we do not use earthly methods to fight the war. It is spiritual armor, truth, righteousness, the gospel of peace, faith, salvation, and the word of God. It is fought with prayer and it is fought with speaking and doing God’s word. We are doers of the word and not hearers only (James 1:22). We aren’t fighting people; we are fighting demonic forces under the lead of Satan. The lost are blindly ignorant prisoners of war to whom we can bring the freedom of Christ. Believer, we have nothing to fear in fighting him. He prowls around, seeks to devour, steal, kill, and destroy (1 Peter 5:8, John 10:10) but he is a coward, easily defeated now, and eternally defeated in the future. We don’t glorify the enemy. We don’t battle him with our words or our power. We battle him with the tools described in the armor of God. We don’t even have to battle, we pray, we have faith, we take thoughts captive (2 Corinthians 10:5), we remember the truth and throw out the lies of the accuser. We resist him, not fight him. He is a coward and he doesn’t stick around for losing battles. James 4:6-8 describes the best way to deal with that gutless enemy.
But he gives more grace. Therefore it says, “God opposes the proud, but gives grace to the humble.” 7 Submit yourselves therefore to God. Resist the devil, and he will flee from you. 8 Draw near to God, and he will draw near to you. Cleanse your hands, you sinners, and purify your hearts, you double-minded.
Be humble, submit yourself to God, resist the devil, draw near to God and cleanse your hands of sin. Resist is defined as to “remain strong against the force or effect of: to not be affected or harmed by.” If we engage the enemy, he remains engaged. If we resist, he flees.
Jesus is the Warrior King. He already won the war when He resurrected after laying down His life for us (Revelation 1:18). Soon, Satan will face defeat and eternal torment (Revelation 20:10).
David the warrior king gained great glory for God and built the fame and reputation of Israel as a people to be feared. Some kings, rather than fight David and his army, chose to submit to him before he could combat them. They recognized his enemies were theirs as well and joined him. Verses 9-14 read,
When Toi king of Hamath heard that David had defeated the whole army of Hadadezer, 10 Toi sent his son Joram to King David, to ask about his health and to bless him because he had fought against Hadadezer and defeated him, for Hadadezer had often been at war with Toi. And Joram brought with him articles of silver, of gold, and of bronze. 11 These also King David dedicated to the Lord, together with the silver and gold that he dedicated from all the nations he subdued, 12 from Edom, Moab, the Ammonites, the Philistines, Amalek, and from the spoil of Hadadezer the son of Rehob, king of Zobah.
13 And David made a name for himself when he returned from striking down 18,000 Edomites in the Valley of Salt. 14 Then he put garrisons in Edom; throughout all Edom he put garrisons, and all the Edomites became David's servants. And the Lord gave victory to David wherever he went.
When we are wearing God’s armor and fighting as God has told us to do, we too will glorify the LORD and people will join His side. When we signed on, we were given a commission. Our commission does not say fight people, hate those who hate you, or argue with non-believers until they believe. Jesus told us,
All authority in heaven and on earth has been given to me. Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age. (Matthew 28:18-20).
Jesus gave us a commandment and told us that by this commandment people would know we were His followers. John 13:34-35 reads,
A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another. By this all people will know that you are my disciples, if you have love for one another.
We have our commission and we have our commandment. We cannot carry these out alone. Jesus didn’t. He had had his disciples. David didn’t. He was surrounded by support. Verses 15-18 read,
So David reigned over all Israel. And David administered justice and equity to all his people. 16 Joab the son of Zeruiah was over the army, and Jehoshaphat the son of Ahilud was recorder, 17 and Zadok the son of Ahitub and Ahimelech the son of Abiathar were priests, and Seraiah was secretary, 18 and Benaiah the son of Jehoiada was over the Cherethites and the Pelethites, and David's sons were priests.
Jesus was not alone. David was not alone. How can we think we can fight the good fight alone? Being together, gathering together in our King’s name is powerful. I can show you verse after verse in God’s Word which shows He expects us to live and walk as a community. In Matthew 18:18-20 Jesus described just how powerful even a few of us together can be.
Truly, I say to you, whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven. Again I say to you, if two of you agree on earth about anything they ask, it will be done for them by my Father in heaven. For where two or three are gathered in my name, there am I among them.
Believer, do you want to be a person after God’s own heart? Then you must take part in the resistance! You are a warrior. You were made to overcome the bondage of evil. You are victorious. Perhaps you should live that way. Put on the whole armor of God.
 David’s son were priests more properly translates to David’s sons were chief officials. They carried out not Godly priestly duties, but ministry and duties to David and officiated as princes and officials in David’s name. See 1 Chronicles 18:17 “… and David's sons were the chief officials in the service of the king.”