The biblical revelation on evil spirits is no less relevant to the way in which the church is to defend herself against the demonic. We are constantly warned that Satan works principally through doctrinal deception and falsehood. His great intent is to bring darkness and confusion into the church as he did among the Jews. The idea that Christianity stands chiefly in danger from the forces of materialism, or from secular philosophy, or from pagan religions, is not the teaching of the New Testament. No one can rightly believe this without seeing the seriousness of error.
Wrong belief is as dangerous as unbelief.
The apostles, filled with the Spirit of Christ, suffered no toleration of error. They opposed it wherever it arose and required the same spirit of all Christians. The explanation often given by Evangelicals for the lack of confrontation with error is that a harsh militancy has done more harm than good. As Christians, it is said, we do not want to be party to the kind of strident controversy which has too often marred the faith. Dr Billy Graham has often blamed 'fundamentalists' for this fault.