Christians in every age have faced battles with their culture. For Noah, it was atheistic anarchy. For Moses, it was the brutality of Egypt. For David, it was the insurgence of the Philistines. For Israel, it was the delights of heathen idols. For those in captivity, it was the comforts of Babylon. For Jesus and the apostles, it was religious legalism. For Augustine and the true church, it was the heresies of Nestorius. For Luther, it was the corruption...