After Jericho fell the people of Israel grew pretty presumptuous. Their next target was Ai. "It's a small town, and it won't take more than two or three thousand of us to destroy it. There's no need for all of us to go there." They sent their small battalion and reduced God to a lethal weapon. The results are almost comical: "The men of Ai chased the Israelites from the city gate as far as the quarries, and they killed about thirty-six who were retreating down the slope. The Israelites were paralyzed with fear at this turn of events, and their courage melted away" (Joshua 7:5, NLT).
Courage founded on presumption will melt. Faith based upon a mechanized view of God will inevitably turn to fear.