God never intended Israel to be a military power; they were always going to have enemies on their borders. He intended for them to take enough land that they would be militarily secure, but they stopped to soon. This resulted in them needing to spend way too much energy, manpower and national treasure on self-defense and not enough becoming the nation that God wanted them to be.
God’s intended for Israel to become a prosperous nation that was a spiritual beacon for the world around them. They were to hold him up as the one and only true God. They were to be blessed in order that they might become a blessing to all nations. Because of their disobedience and failure to follow through on God’s plan, they were not able to become the nation God wanted them to be.
The most tragic result of their disobedience was not the enemies upon their borders; God could always protect them. The true tragedy was the result of allowing the Canaanites, Hittites, Amorites, Perizzites, Hivites and Jebusites to live among them. The Israelites married the sons and daughters of the foreigners. That did not have to results in disaster. If the Israelites had been strong enough in their faith to convert the nonbelievers in their midst it would have been a victory. They were not strong in their faith, and instead of leading others to God, they begin to worship the pagan gods of the nations around them.
The church does not need a military; we are not forming our own nation. We are a part of the kingdom of God, and are content let the nations of the world settle their own disputes. We are involved in spiritual conflict, and that conflict starts within the church itself. We must be vigilant against the influences of worldliness. Our mission is to change the world, and we cannot do that by allowing the world to change us. A church that is corrupted by the world cannot be a blessing to the world.