When we read the Old Testament, we get the impression that there appears to have been almost continual warfare in the Ancient Near East, particularly between Israel and her neighbours, and with the great empires of Assyria and Babylon.
The term 'holy war' is rather misleading, as it makes it appear that warfare is morally good, but the term refers to the popular understanding of the nature of warfare in Old Testament times. War was not only between two nations, but involved their gods as well.
Gods of nations
Each nation had their own god, so each god had control of a limited geographical area and one particular people. All the pagan nations around Israel were polytheistic, believing in many different gods, in great contrast to Israel’s belief in one God. None of the nations surrounding Israel believed in a single almighty all-powerful god. The continual challenge for Israel throughout its history was to believe that Yahweh was not merely yet another regional god, who controlled a limited geographical area, but that he was the all-powerful Creator-God of the whole world, who ruled over every nation.
The local nature of gods is shown in one particular conflict between Syria and Israel, when the Syrian army was defeated by Israel. The servants of the king of Aram (Syria) believed this defeat was because they had fought Israel on the hills, where their gods (meaning Yahweh) were stronger. They suggested that if they fought Israel on the plain, then they would be confident that their army would be victorious (1 Kg 20:23-25). The servants of the king of Aram said to him, “Their gods are gods of the hills, and so they are stronger than we; but let us fight against them in the plain, and surely we shall be stronger then they.” They evidently believed that the god(s) of Israel only had power in the hills, and that his power would be limited on the lower ground, on the plain. The Syrian gods had power on the plain, where they would be able to overcome Israel’s god, allowing their army to be victorious.
Going to war
In the general understanding of the Ancient Near East, when one nation went to war against another nation it was because their god was fighting against the god of the foreign nation. Behind each army was the god of that nation. For example, Assyria always fought by the power of their god Ashur (sometimes spelt 'Asshur'), who was the ancestor of their people and founder of their nation (Gen 10:22). In Assyrian carved reliefs showing battle scenes, Ashur was represented by a human figure in a winged disk, often holding a bow and arrow, shown in the sky above the armies.
Israel also had this understanding, as one of the frequently used titles for God in the Old Testament was 'the LORD of hosts'. This is most often used in the books of Samuel, where Yahweh was the God of the armies of Israel, who fought on behalf of his people. David came against Goliath in the name of the LORD of hosts, the God of the armies of Israel (1 Sam 17:45), and believed that God would deliver Goliath into his hands. His victory would be a testimony so the whole earth may know that there is a God in Israel (17:46).
When Joshua was about to attack Jericho, a man appeared before him with a drawn sword (Josh 5:13). He told Joshua that he was the commander of the army of the LORD. In response, Joshua fell on his face and worshipped him (5:14), thus indicating this was no mere man, but a manifestation of God himself, the God of the armies of Israel, who will give them victory over Jericho and the land he had promised Israel.
Victory and defeat
If one nation defeated another nation it was because their god was stronger. To show their victory, the victorious army seized the idols from the defeated enemy. They then took the idols back to their home city, installing them in the temple of their god. The victory demonstrated that their god was more powerful than the god of the enemy.
These principles of 'holy war' can be seen in the accounts of a number of different battles in the Old Testament. Each of these narratives reveal some of the popular understanding of warfare among the nations, as well as the lessons God was teaching his people, to challenge this understanding.
Israel and the Philistines (1 Sam 4)
After an initial defeat by the Philistines, the elders of Israel suggested that they bring the ark of the covenant from Shiloh, so the LORD may come among them and save them from the power of their enemies (4:3). When the ark arrived in the Israelite camp, all Israel gave a great shout, which drew the attention of the Philistines (4:5). The Philistines were afraid at this development, saying, “Gods have come into the camp.”, and wondering who can deliver them from the power of these mighty gods who had struck the Egyptians with every sort of plague (4:7-8). They evidently thought that the ark of the covenant had particular power, being Israel’s god.
In the subsequent battle Israel was thoroughly defeated and the ark was captured (4:10-11). The Philistines then brought the ark to Ashdod and placed it in the house of their god, Dagon (5:1-2). Their intention would have been to demonstrate that Dagon was more powerful than Yahweh, because Israel’s armies had been defeated by the armies of the Philistines. After the first night they found that Dagon had fallen face down before the ark of the LORD, so they had to put him back in his place (5:3). However, after the second night, Dagon had again fallen down before the ark of the LORD, but this time his head and hands had broken off (5:4). God then struck the people of Ashdod with tumours (5:6), so they moved the ark to Gath, where the people were also struck with tumours (5:8-9). In desperation, they finally sent the ark back to Israel.
The Philistines mistakenly believed their god, Dagon, had defeated Israel’s God. It is probable that Israel also understood events in this way. However, the Philistines had defeated Israel because God allowed them to, as judgement on the sins of the sons of Eli (3:11-14). Instead of being a regional god who had been defeated by a more powerful god, Yahweh was God of all nations, who had exercised his sovereignty over all nations to cause Israel to be defeated by the Philistines, as a punishment for their iniquity.
Sennacherib’s siege of Jerusalem - 701 BC (Is 36-37)
When the Assyrian army besieged Jerusalem in 701 BC, the Rabshakeh (the representative of the Assyrian king, Sennacherib) tried to confuse the people. He challenged them not to be deceived by King Hezekiah into thinking that Yahweh could deliver them from the armies of Assyria. “Do not let Hezekiah deceive you, for he will not be able to deliver you. Do not let Hezekiah make you rely on the LORD by saying, “The LORD will surely deliver us; this city will not be given into the hand of the king of Assyria” (Is 36:15). He asked, “Has any of the gods of the nations saved their land out of the hand of the king of Assyria?" (Is 36:18b), then listed several defeated nations. They were convinced that their own god, Ashur, had defeated the gods of the all the nations they had already conquered, and did not believe that Yahweh would be powerful enough to save Jerusalem (Is 36:20). The Assyrians had conquered many nations, so their god must be stronger.
In response, Hezekiah prayed to the LORD of hosts, the God of the armies of Israel, who is God over all kingdoms, including Assyria (37:16). He prays: “O LORD of hosts, God of Israel, who are enthroned above the cherubim, you are God, you alone, of all the kingdoms of the earth; you have made heaven and earth.” (37:16). Hezekiah believed in a God who is totally different from idols of wood and stone which have been thrown aside by Assyria. He knows that Israel’s God is the only God, the creator of heaven and earth, and ruler over all the kingdoms of the earth, including Assyria. Hezekiah then called on God to show his power and deliver Jerusalem from the Assyrians (36:20).
The words that came through Isaiah in response to his prayer remind the king that God is the all-powerful ruler of the nations, and that he had planned from long ago that he would use Assyria to bring fortified cities into ruins, and that the pride of Assyria would be humiliated, when they were turned around and dragged home (36:26-29).
That night the angel of the Lord slew 185,000 soldiers of the Assyrian army outside the city of Jerusalem (37:36) - a great deliverance for Hezekiah and a vindication of his faith in Yahweh.
One of the important messages through the Book of Isaiah is that God is the Almighty, the creator and ruler of nations, who is no local regional god, but one who whistles and the armies of the nations start to march, whether Egypt and Assyria (7:18-19), or later Persia (41:2). “He will raise a signal for a nation far away, and whistle for a people at the end of the earth; Here they come, swiftly, speedily! None of them is weary, none stumbles, none slumbers or sleeps, not a loincloth is loose, not a sandal-thong broken; their arrows are sharp, all their bows bent, their horses’ hoofs seem like flint, and their wheels like the whirlwind ...” (Is 5:26-28).
Capture of Jerusalem by Babylon - 586 BC
When the Babylonians captured and destroyed Jerusalem in 586 BC, they took the sacred vessels used for the sacrifices from the temple to Babylon (2 Kg 25:13-17, 2 Chr 36:18), where they placed them in the house of their gods (Ezra 1:7). This would be to demonstrate that their god, Marduk, was more powerful than Israel’s god, because the armies of Babylon had conquered and destroyed Jerusalem and its temple. Evidently they took the sacred vessels because there was no idol to take, and the ark of the covenant had been destroyed, or disappeared. The sacred vessels were the best they could find.
During Belshazzar’s feast, the king commanded that these vessels of gold and silver from the temple in Jerusalem be brought in, so he and his guests could drink from them. As they did so, they praised their gods (Dan 5:2-4). This act would be a celebration of the power of Marduk, and a humiliation of Israel’s god. At that exact moment the hand appeared and wrote on the wall (5:5), writing words which Daniel later interpreted, saying that Belshazzar’s kingdom had come to an end (5:24-28). God was not going to allow his sacred vessels to be desecrated in this way, and his name mocked by a pagan king. That night the armies of Persia captured Babylon and Belshazzar was killed.
When the first group of Jews left Babylon to return to Jerusalem, King Cyrus himself brought these temple vessels and gave them to the returning exiles (Ezra 1:7). There were over five thousand different vessels (1:11). The Jews later reminded King Darius that Cyrus had given them these vessels when they wrote to the king to complain about the opposition to building the temple (Ezra 5 14-15). The decree of Cyrus is recorded in the king’s reply, which again mentions these vessels (6:3-5).