A nation's military personnel organized for battle. Thus in Egypt, Israel could be referred to as having “armies” even when they did not have a political organization (Exodus 6:26;
Exodus 12:17). Goliath learned that to defy God's people was to defy the “armies of the living God” (1 Samuel 17:26,1 Samuel 17:36), for God was the “God of the armies of Israel” (1 Samuel 17:45). In face of God, humans can only confess, “Is there any number of his armies?” (Job 25:3). Israel recognized God's anger when God did not go out with their armies (Psalms 44:9). To announce salvation, the prophet proclaimed the fury of God upon all armies (Isaiah 34:2). In the New Testament the writer of Hebrews looked back on the heroes of faith and proclaimed that through faith they “turned to flight the armies of the aliens” (Hebrews 11:34). John's vision of the end time included the armies of heaven following the King of kings to victory over the beast and the false prophet (Revelation 19:11-21).
Armies were organized in different ways during Israel's history. The patriarchs called upon servants and other members of the household (Genesis 14:1). In the wilderness Joshua led men he had chosen to defend against the Amalekites (Exodus 17:9-10). In the conquest Joshua led the tribes of Israel into battle after being commissioned by the “captain of the host of the Lord” (Joshua 5:14). At times tribes joined together to take territory (Judges 1:3;
Deborah summoned many of the tribes to battle, but some did not answer (Judges 5:1). Other judges summoned clans (Judges 6:34) and tribes (Judges 6:35;
Judges 7:29). Saul first established a standing, professional army in Israel (1 Samuel 13:2), at first leading it himself with his son but then appointing a professional commander (1 Samuel 17:55). David apparently hired foreign troops loyal to him personally (2 Samuel 9:18;
2 Samuel 15:18). Solomon enhanced the foot soldiers with a chariot corps and calvary (1 Kings 10:26). The army was organized into various units with officers over each, but the precise chain of command cannot be determined (2 Chronicles 25:5). Humanitarian laws determined who was excused from military service and how war was conducted (Deuteronomy 20:1).