The conception of religion presupposes, a, God as object; b, man as subject; c, the mutual relation existing between them. According to the various stages of development which men have reached, religious belief manifests itself either in the form of a passive feeling of dependence, where the subject, not yet conscious of his independence, feels himself wholly overmastered by the deity, or the object of worship, as by a power outside of and opposed to himself; or, when the feeling of independence has awakened, in a one-sided elevation of the human, whereby man in worshiping a deity deifies himself. In the highest stage of religious development, the most entire feeling of dependence is united in religion with the strongest consciousness of personal independence. The first of these forms is exhibited in the fetich and nature-worship of the ancient nations; the second in Buddhism, and in the deification of the human, which reaches its full height among the Greeks. The true religion, prepared in Israel, is the Christian, in which man, grown conscious of his oneness with God, is ruled by the divine as an inner power of life, and acts spontaneously and freely while in the fullest dependence upon God. Since Christ, no more perfect religion has appeared. What is true and good in Islamism was borrowed from Israel and Christianity.
Although it is probable that every nation passed through different forms of religious belief before its religion reached its highest development, yet the earlier periods lie in great part beyond the reach of historical investigation. The history of religion, therefore, has for its task the review of the various forms of religion with which we are historically acquainted, in the order of psychological development.