The Kingdom of God is Within You by Leo Tolstoy

Thus, both the information received by me after the publication of my book, as to how the Christian teaching in its direct and true sense has without interruption been understood by the minority of men, and the criticisms upon it, both the ecclesiastic and the lay criticisms, which denied the possibility of understanding Christ's teaching in the direct sense, convinced me that, while, on the one hand, the true comprehension of this teaching never ceased for the minority, and became clearer and clearer to them, on the other hand, for the majority, its meaning became more and more obscure, finally reaching such a degree of obscuration that men no longer comprehend the simplest propositions, which are expressed in the Gospel in the simplest words.

The failure to comprehend Christ's teaching in its true, simple, and direct sense in our time, when the light of this teaching has penetrated all the darkest corners of human consciousness; when, as Christ has said, that which He has spoken in the ear, they now proclaim upon the housetops; when this teaching permeates all the sides of human life -- the domestic, the economic, the civil, the political, and the international -- this failure to comprehend would be incomprehensible, if there were no causes for it.