The Lord Is a Warrior!
I think even a quick read of the Old Testament would be enough to convince you that war is a central theme of God's activity. There is the Exodus, where God goes to war to set his captive people free. Blood. Hail. Locusts. Darkness. Death. Plague after plague descends on Egypt like a boxer's one-two punch, like the blows of some great ax. Pharaoh releases his grip, but only for a moment. The fleeing slaves are pinned against the Red Sea when Egypt makes a last charge, hurtling down on them in chariots. God drowns those soldiers in the sea, every last one of them. Standing in shock and joy on the opposite shore, the Hebrews proclaim, "The LORD is a warrior!" (Ex. 15:3). Yahweh is a warrior.
Then it's war to get to the Promised Land. Moses and company have to do battle against the Amalekites; again God comes through, and Moses shouts, "The LORD will be at war against the Amalekites from generation to generation" (Ex.17:16). Yahweh will be at war. Indeed. You ain't seen nothin' yet. Then it's war to get into the Promised Land-Joshua and the battle of Jericho, and all that. After the Jews gain the Promised Land, it's war after war to keep it. Israel battles the Canaanites, the Philistines, the Midianites, the Egyptians again, the Babylonians-and on and on it goes. Deborah goes to war; Gideon goes to war; King David goes to war. Elijah wars against the prophets of Baal; Jehoshaphat battles the Edomites. Are you getting the picture?