Machen writing in 1923:
[...] a remarkable change has come about within the last seventy-five years. The change is nothing less than the substitution of paganism for Christianity as the dominant view of life. Seventy-five years ago, Western civilization, despite inconsistencies, was still predominantly Christian; today it is predominantly pagan.
In speaking of "paganism," we are not using a term of reproach. Ancient Greece was pagan, but it was glorious, and the modern world has not even begun to equal its achievements. What, then, is paganism? The answer is not really difficult. Paganism is that view of life which finds the highest goal of human existence in the healthy and harmonious and joyous development of existing human faculties. Very different is the Christian ideal. Paganism is optimistic with regard to unaided human nature' whereas Christianity is the religion of the broken heart.In saying that Christianity is the religion of the broken heart, we do not mean that Christianity ends with the broken heart; we do not mean that the characteristic Christian attitude is a continual beating on the breast or a continual crying of "Woe is me." Nothing could be further from the fact. On the contrary, Christianity means that sin is faced once for all, and then is cast, by the grace of God, forever into the depths of the sea. The trouble with the paganism of ancient Greece, as with the paganism of modern times, was not in the superstructure, which was glorious, but in the foundation, which was rotten. There was always something to be covered up; the enthusiasm of the architect was maintained only by ignoring the disturbing fact of sin. In Christianity, on the other hand, nothing needs to be covered up. The fact of sin is faced squarely once for all, and is dealt with by the grace of God. But then, after sin has been removed by the grace of God, the Christian can proceed to develop joyously every faculty that God has given him. Such is the higher Christian humanism--a humanism founded not upon human pride but upon divine grace.
But although Christianity does not end with the broken heart, it does begin with the broken heart; it begins with the consciousness of sin.
(italics mine; p56–57, Christianity and Liberalism)