Conflicting Christian attitudes
The history of religion, however, continued even after Christ. During the 3rd and 4th centuries a new world religion appeared in the form of Manichaeanism, which asserted itself as a superior form of Christianity with a new universal claim of validity. The Christian church never acknowledged the claims of Manichaeanism but considered the religion a Christian heresy and opposed it as such.
Christianity faced greater challenges when it encountered Islam and the religions of East Asia. When Islam was founded in the 7th century, it considered the revelations of the Prophet Muhammad to be superior to those of the Old and New Testaments. Christianity also fought Islam as a Christian heresy and saw it as the fulfillment of the eschatological prophecies of the Apocalypse concerning the coming of the “false prophet” (Revelation to John). The religious and political competition between Christianity and Islam led to the Crusades, which influenced the self-consciousness of Western Christianity in the Middle Ages and later centuries. In China and Japan, however, missionaries saw themselves forced into an argument with indigenous religions that could be carried on only with intellectual weapons. The old Logos theory prevailed in a new form founded on natural law, particularly among the Jesuit theologians who worked at the Chinese emperor’s court in Beijing. The Jesuits also sought to adapt indigenous religious traditions to Christian rituals but were forbidden from doing so by the pope during the Chinese Rites Controversy.
Philosophical and cultural developments during the Enlightenment brought changes in the understanding of Christianity and other world religions. During the Enlightenment the existence of the plurality of world religions was recognized by the educated in Europe, partly—as in the case of the German philosopher Gottfried Wilhelm Leibniz—in immediate connection with the theories of natural law of the Jesuit missionaries in China. Only in the philosophy of the Enlightenment was the demand of tolerance, which thus far in Christian Europe had been applied solely to the followers of another Christian denomination, extended to include the followers of different religions.
Some missionaries of the late 18th and19th centuries, however, ignored this knowledge or consciously fought against it. Simple lay Christianity of revivalist congregations demanded that a missionary denounce all pagan “idolatry.” The spiritual and intellectual argument with non-Christian world religions simply did not exist for this simplified theology, and in this view a real encounter of Christianity with world religions did not, on the whole, occur in the 18th and 19th centuries.