Some time ago I wrote a kind of Bible study on the issue of war. The war in Iraq and the current terrorism are making the issue of war a very relevant one for many people. I like to share some insight from the Old Testament first.

 
  I   An Old Testament perspective on war
War has been part of the human history since sin entered the world. It started as a war between two brothers, where the innocent and righteous one, was murdered. Throughout the OT we find numerous accounts of wars. War was almost viewed as something natural and inevitable.  "A time for war and a time for peace" (Ecc.3:8) "As no one is discarged in time of war, so wickedness will not release those who practice it." (Ecc.8:8) Sometimes war seems to be a seasonal happening and the spring was "the time when kings go off to war." (1.Chron.20)
There was a very close relationship between the religion of Israel and war. We can see that from the beginning and through the whole history of Israel. In OT we find the religious importance of war in three forms of war: The holy war, war as judgement of God and the eschatological war.
  1. The holy war.
  a. The first Messianic prophecy
The thought of a holy war can be traced back to the first Messianic prophecy in Gen.3:15: "And I will put enmity between you and the woman, and between your offspring and hers, he will crush your head, and you will strike his heel." The antagonism between the offspring – seed – of the woman and the offspring of the serpent is played out in the hearts and history of mankind as the struggle between God and devil, good and evil. Christ’s victory over Satan is secured and will be worked out in time and space and all the believers will share his victory. (Rom.16:20)
  b. The Kingdom of God and Israel
Now, in OT the history of the Kingdom of God is closely related to the history of Israel. Israel is the people of God (Ex.19:6; Deut.7:6) and the enemy directs his attacks on this people that is to communicate the word of God to the world and bring forth the Messiah, the Saviour. (Rom.3:2; 9:5; Gen.22.15-18.) This people had to be kept to fulfil it’s destiny, (Gen.12:3; Ex.23:22) and therefore their wars are "the wars of the Lord" (Num.21:14, 1.Sam.18:17; 25:28; 2.Chron.20:15).
  c. The Lord is a warrior
"The Lord is a warrior" (Ex.15:3; Isa.42:13; "The Lord mighty in battle" (Ps.24:8) and the name "The Lord of hosts, Yahweh Sebaoth" (Isa.6:3) signify that God is the Almighty Ruler of the heavenly hosts and all resources and the fact that he is "God of the armies of Israel". (1.Sam.17:45)
The Lord is the one who goes with his people to fight for them. (Deut.20:4) The Lord is their leader (2.Chron.13:12), he is the commander of the army of the Lord (Joshua.5:13-15). He trains his people for battle (Ps.18:34; 144:1), he sends his people to war (2.Chron.6:34) and he delivers the enemies in their hands (Deut.20:13; 28:7) In confidence to the Lord, the great and awesome, the people is to fight for their families (Neh.4:14). Sometimes the Lord himself take care of the battle and the army of Israel just have to stand still to see how the Lord fights for them (Ex.14:14,25fl; Jos.10:14; 2.Chron.20:17).
  d. To consecrate war = to prepare for war
It was the will of God for Israel to fight for her freedom and existence as a people. Sometimes war was a direct command of the Lord. (Deut.7:1fl; 31:1fl; Judges 6:14fl.; 14:4fl.; Ex.17:14fl.; Num.24:20; Deut.25:19; 1.Sam.15:2,3,20)
Since the war was a war of the Lord, it was a holy war. To consecrate war = to prepare for war (Jer.6:4 qiddes milhama) and that required special offerings (1.Sam.13:9 compare 7:7-11). One also required a word from the Lord, the counsel of the Lord, and the prophets to prophecy (1.King.22:5fl.; 2.King.3:11fl.) or one did some symbolic acts according to the prophet’s instruction (2.King.3:16fl.; 13:14-19).
The camp of Israel was expected to be holy, (Deut.23:14) and it was required that the soldiers dedicated or consecrated themselves before the Lord. (See Isa.13:3 where the soldiers are called my consecrated ones). Among other things the soldiers had to abstain from sexual intercourse, (2.Sam.11:11fl compare 1.Sam.21:4fl.) and sometimes from food, (Judges 20:26 1.Sam.7:6fl.; 14:24). Even if the soldier was viewed to be specially consecrated for his task, he needed to be cleansed before he could enter the camp! (Num.31:19)
  e. Participating in war disqualified a man of God to build the house of God
It is remarkable that the hero-king David who fought the wars of the Lord, was not allowed to build the Temple of God "because you have shed much blood on the earth in my sight and fought many wars". (1.Chron.22:8) The soldiers needed to be cleansed before they were allow to enter the camp of Israel.
  f. Wars will come to an end – military equipments will be destroyed
The view that war is evil and will be put to an end comes trough very clearly also in the Messianic prophecies. (Isa.2:4; Mi.4:3; Zec.9:10) In the coming Messianic age, the Messiah will take away the chariots and war-horses and the battle bow will be broken. He will proclaim peace to the nations and his rule will extend from sea to sea, even to the ends of the earth. Weapons will be made unto farming tools, and people will no longer train for war. Every warrior’s boot and uniform will be destined for burning. The peace and the rule of Messiah will be universal. (Ps.22:27-28; 72:8-11; Isa.9:2-7; 11:9-10; 40:3-5; 45:22; 52:10; 66:18)
The only war that the OT support is the war of the Lord, the holy war, but even then the men engaged in war were in need of cleansing and were restricted to what they could do for the Lord after their cleansing.
  g. Unholy war – breaking the covenant of brotherhood
The war between the kingdom of Judah and the kingdom of Israel was seen as a war between brothers and was condemned as sinful. (1.King.12:21-24; 14:30; 15:6,16,32) This war became even worse when the two parties engaged heathen kings to help them in their war against their brothers. (2.Kings 16:1-18)
The transgression of Tyre was to war against Israel, their brothers by covenant, to take captive whole communities to sell them. (Amos 1:9; 1.Kings 5:1,12; 9:13-14)
When the heathen warrior-people attacked her neighbours "more righteous than themselves", then it was viewed as evil. (Hab.1:13)
  2. War as judgement
  a. Judgement of God on wicked nations
We find in the OT that war was viewed as a judgement because of the sins of the nations. When Israel fought against the inhabitants of Canaan to possess the promised land, this was the background. The sin of the Amorites had to reach its full measure (Gen.15:16) before the Israelites could take the land.
Later we often find this thought that war is a judgement of God on wicked nations. Amalekites 1.Sam.15:2-3; Egypt Jer.46:10-26, Isa.19:2; Philistines Jer.47:1-7; Moab Jer.48; Ammon Jer.49:1-6, Ezek.21:28-29; Edom Jer.49:8-22; Syria Jer.49:27; Arabia Jer.49:32; Babylon Jer.50 + 51, Isa.13; Tyre Isa.23; etc.
  b. Judgement on Gods people
Even against the people of God, war could be used as judgement when they fell from the Lord and worshiped idols. (2.Kings 15:37; Isa.5:25-30; Jer.5:15-19; Am.5:27; 6:14); "For this is what the Sovereign Lord says: How much worse will it be when I send against Jerusalem my four dreadful judgements – sword and famine and wild beasts and plague – to kill its men and their animals." (Ezek.14:21). When the Lord in this way had to discipline his people with war, it was a sign of obduracy and lack of repentance if the people just fought against their enemies without humbling themselves before the Lord first. (Jer.21; 27; Isa.22:8-14) The Lord himself take the lead of the enemy armies to bring them to war against Israel. But the same armies will always be destroyed by God. (Isa.10:5-9; Jer.51:59-64).
  3. The eschatological war.
The OT revelation teaches us that the world history will reach its completion through a great and l
ast conflict between good and evil, and that this crisis will be followed by the Messianic Kingdom, where Messiah the prince of peace rules, Isa.9. There is no development towards a peaceful age, but wickedness and godlessness will reach its culmination in a great end-time-war, where the wicked peoples will attack God’s people that will be threatened by annihilation, (Ezek.38; Joel 2; Zech.14:1-2).
"The kings of the earth take their stand and the rulers gather together against the Lord and against his Anointed One." (Ps.2.1-3; Dan.7:8,23-28) Then the Lord will go out and fight those nations. (Zech.14:3). He gathers them to pour out his wrath on them. (Zeph.3:8; Joel 3:12; Isa.13:6-13; 24); "When the power of the holy people has been finally broken, all these things will be completed." (Dan.12:7). Then the Lord intervenes. After all godless powers have been defeated, the Messianic Age of peace will break forth, when in the end all weapons will be transformed into farming tools and people will no longer train for war. (Isa.2:4; 11:1-10; Micah 4:3-4; Zech.9:10).