Christianity spread eastward as well as westward, in the process evolving various differences from place to place in doctrine and forms of worship. The Christianity of the Silk Road was primarily the form known as Nestorianism, after the teachings of Nestorius, a 5th-century patriarch of Constantinople who soon outraged the Roman and Byzantine worlds with his unorthodox doctrines, such as taking from the Virgin her title “Mother of God.” Nestorian Christianity spread to Persia, India, and China, bringing with it the Syriac language and script ( the basis of the writing systems of several Central Asian languages); a famous inscribed stela (standing stone tablet) in Xi’an, dated 781, commemorates the official arrival of Nestorian missionaries in China. By that time, Nestorian churches were to be found in cities all along the Silk Road, though there were undoubtedly many fewer Christians than Buddhists in Central Asia.
Another Middle Eastern faith that was important on the Silk Road for a time was Manichaeism, established by the Persian prophet Mani in the 3rd century CE. Mani arose from the Zoroastrian tradition, and consciously incorporated elements of Zoroastrianism, Christianity, Hinduism, Buddhism, and other faiths into his own doctrines; he saw himself as the successor to Zoroaster, the historic Buddha, Jesus, and other great ancient religious teachers. Manichaeism, like Zoroastrianism, emphasized the struggle between good and evil, light and darkness; it offered salvation to the Elect, those who were deeply immersed in the faith’s teachings. Manichaeism became an important rival of Christianity in the Middle East and Mediterranean North Africa, and was known all along the Silk Road (though with little or no impact on China and East Asia), but its influence began to wane by the end of the 6th century.
Silk Road faiths from the Middle East to the north western reaches of China were challenged and, in time, displaced by the spread of Islam, which is at present the faith of the majority of people in the countries spanned by the old Silk Road.
Muhammad, the Prophet of Islam, was born around 570 CE. At the age of40, according to Muslim tradition, he became the recipient of a series of revelations, recorded in the Quran, which is for Muslims a faithful recording of the entire revelation of God sent through Muhammad. The basic teachings of the Quran were belief in One God, unique and compassionate; the necessity of faith, compassion, and morality in human affairs; accountability of human actions; and the recognition that the same God had sent Prophets and Revelations to other societies, which Islam affirmed while regarding the Quran as the final message and Muhammad as the last of the divine messengers.
Although the initial spread of Muslim rule and authority to neighboring regions, which took place after the death of the Prophet in 632, was a result of conquest, the actual process of converting the peoples in these regions to Islam took a long time. It was effected primarily through the work of Muslim preachers, traders, and rulers. On the whole, the process of conversion to Islam, with a few exceptions, was a peaceful one. Most Muslims followed the Quranic injunction “There is nocompulsion in religion” (Ch.2:256) and spread their faith more by example than by coercion.
In the Silk Road context, a good example of this process are the Sufis, devotees committed to spiritual life and unity among traditions, whose teachings of Islam exist in all the vernaculars and cultures of Silk Road peoples. The full diversity of Muslim traditions, schools of thought, and civilizing influences have flourished along the Silk Road. These include the development of philosophy and science; law and history; literature and the arts; and the expressions in music and dance of the devotional and creative spirit of Islam. That pluralism still denies the life of most Muslims living along the old Silk Road. At present, at least 560 million Muslims live in Asia, almost half of the total number of Muslims in the world.