It is astonishing that studies of the work of Christ have not yielded clearer and more systematic distinctions between the different dimensions of the work of his death. Evangelical Christianity does distinguish between sins and sin, fruit and root; but the third dimension, the work of Satan, is seldom acknowledged, even where Satan and his work are recognized. Yet for a total unmasking of evil in the human heart the third dimension is necessary, since the person and work of the devil is the greatest hindrance to mature Christianity. Satan loves it so. That is doubtless why it is so, and why so many are suspicious of talk about the devil and demons. Yet it is a strange blindness with which the god of this world has blinded so many professing Christians (2 Cor. 4:4).
-William Still, Towards Spiritual Maturity, pg. 14-5.