God told Israel they would cross the Jordan and conquer many superior forces. If they would act in His name, victory was certain. God is unified in purpose. He is not double-minded. He does not "bait-and-switch". If he promises to give us victory, then we will have victory **if we act according to his will**. Our God is a consuming fire and nothing can resist him or his agents! Keep the commandments and cross the Jordan. Let God worry about the rest.
Deuteronomy 9:1-3