There are certainly false teachers in the world, but when they exist in the church, and unopposed, they are the most dangerous. We need to be aware that they exist, and we need to know how they work. We should not be "ignorant of his (i.e., the Devil's) devices" (2 Cor. The Lord intended for elders in each local church to be the primary line of defense against every threat to the faith. This is why Paul charged the Ephesian elders to take heed to themselves first (Acts But what happens when that line of defense fails?