The efficacy of religion lies precisely in what is not rational, philosophic or eternal; its efficacy lies in the unforeseen, the miraculous, the extraordinary. Thus religion attracts more devotion according as it demands more faith,—that is to say, as it becomes more incredible to the profane mind. The philosopher aspires to explain away all mysteries, to dissolve them into light. Mystery on the other hand is demanded and pursued by the religious instinct; mystery constitutes the essence of worship, the power of proselytism. When the "cross" became the "foolishness" of the cross, it took possession of the masses.

Bartlett's Familiar Quotations, 10th ed. (1919) - Journal