The dynamics of the spread of beliefs along the Silk Road involves a crucial, though little-remarked, difference between two fundamental types of religions. Generally speaking, religions are either proselytizing or non-proselytizing. That is, they either actively seek to recruit new members to the faith from outside the current membership group, or they do not. In the former case, ethnicity, language, color, and other physical and cultural differences are taken to be of relatively small importance compared with the common humanity of all believers, and the availability of the faith (and its particular canons of belief, forms of worship, and promises of salvation) to all humans everywhere. In the latter case, that is, of non-proselytizing religions, membership in a religion often coincides with membership in an ethnic group, so that religious participation is a birth right and not a matter of conversion; conversion often occurs only when a person marries into the faith, and in extreme cases conversion is rejected as an impossibility. Examples of proselytizing faiths are Zoroastrianism, Manichaeism, Buddhism, Christianity, and Islam; non-proselytizing faiths include Hinduism, Judaism, and Shinto. All of these were religions of the Silk Road; some spread along the trade routes to extend their spheres of faith enormously, while others did not travel from their native lands, or did so only to form enclaves of the faithful in foreign lands.
Buddhism was the first of the great missionary faiths to take advantageof the mobility provided by the Silk Road to extend its reach far beyond its native ground. From its origins in north eastern India, Buddhism had already spread into the lands that are now Pakistan and Afghanistan by the 1st century BCE. Buddhist merchants from those areas built temples and shrines along the Silk Road everywhere they went; the priests and monks who staffed those religious establishments preached to local populations and passing travelers, spreading the faith rapidly. Buddhism’s essential message—that earthly life is impermanent and full of suffering, but that the painful cycle of birth, death, and rebirth can be ended through Buddhist faith and practice—had wide appeal, and its universalism enabled it to cross boundaries of space, language, and ethnicity with ease.
The arrival of Buddhism in China was officially noted by the imperial court in the mid-1st century CE, and the faith spread in China thereafter, helped by both official and private support for the building of temples and monasteries. Buddhist missionaries from Central Asia began an active program of translating sacred texts into Chinese, and a number of Chinese priests and monks, over the centuries, traveled the Silk Road in search of doctrinal instruction in India. Buddhism spread from China to Korea and Japan by the 6th century CE; it retained a dominant position in China until the decline of the Tang dynasty in the 9th century. Thereafter Buddhism remained important in China, but more as a private than an officially sponsored religion.
Buddhism also interacted in China with religious Daoism, especially from the 3rd century CE. Religious Daoism, in the form of several competing sects, absorbed many of the local religious temples and doctrines of ancient China. It offered believers immortality or reincarnation in a celestial pantheon, and amassed a canon of sacred texts rivaling that of Buddhism. Daoism spread westward into CentralAsia along the Silk Road, providing, just as Buddhism had done, religious facilities for traveling believers; many of the important Buddhist temple complexes of Central Asia show Daoist influence or incorporate Daoist chapels. The Chinese Chan tradition of Buddhism (called “Zen” in Japanese) owes a great deal to Buddhist-Daoistsyncretism.
Meanwhile, in the western reaches of the Silk Road, important changes were also taking place. Christianity was transformed, in the century orso after 50 CE, from a local phenomenon in the region now comprising Israel and Palestine to a rapidly expanding, proselytizing religion through the efforts of the major Christian apostles. Christianity thrived especially at the expense of classical paganism; in Christianity’s original homeland, Judaism remained the dominant butnon-proselytizing religion even as it also evolved new traditions of study and practice.