All religions have crossed the Silk roads at all times. Already in mythology, we have elements of Egyptian religion arriving on the Tibetan Plateau, where a Book of the Dead exists in like in Egypt; Buddhism, Mazdeism, Manichaeism, have arrived into China via Sogdiana; Islam has crossed the Silk Road up to Samarkand and Hui mosques exist all over China.
Especially Christianity crossed the Silk Road in an impressive way. Apart from the disputed pretended travels of Christ in India claimed by Indus and Ahmadiyya, less controversial is the activity of Saint Thomas in Chennai (Tamil Nadu). I have visited his cell on Mount Chennai and in Sao Tome, a suburb along the coast, where, according to a legend, he had been killed. In Dravidic India, several Christian confessions still exist claiming their origin from Saint Thomas.
The first peoples of the Middle East to be converted to Christianism were Syrians, Cartvelians and Armenians kingdoms existing among Roman and Persian Empires between Euphrates and Caucasus (Edessa, Caucasian Albania and Iberia). The Syrian Nestorians, followers of the Constantinopolitan Archbishop Nestorius, flying from the Roman Empire because of his condemnation by the Council of Ephesus, and, then, supported by the Persian Emperors, settled everywhere in Asia.
In the 7th Century, under the Tang Dynasty, the Syrian Nestorian monk Rabban (A-luoben in Chinese, crossed the border with China and came to Chang’An (today’s Xi’An), bringing with him the Holy Gospel. At the same time, “the Jesus Sutras” were produced Emperor TaiZong had the Gospels translated and granted to Nestorians, baptized “The Enlightened Doctrine of DaQin” (Rome), the privilege of being a recognized religion of China. The DaQing Stele, with a summary of the “Sutras” and of the history of Chinese Nestorianism, and the “DaQin Pagode” (the main church of Nestorians in China) are still visible in Xi’an.
In the 13th century, Giovanni da Pian del Carpine had been charged of a mission at the Court of the Mongolian Khan, and wrote a report for the Pope, which is known as the Historia Mongalorum. Later on, Khubilai Khan sent to the Pope, via the Polo brothers, a message, asking him to send missionaries to China. The Pope appointed Giovanni da Montecorvino, who translated the Bible into the Chinese language. After a certain time, no bishop was appointed to Beijing any more, because the Black Death had rendered it too dangerous to travel up and down the Silk Road.
When Vasco da Gama opened the road to Indies via the Cape of Good Hope Christian missionaries, and especially the Jesuits, flocked towards India, Japan and China. Especially in China, they played a special role, studying the Chinese and teaching the European culture, advising the Emperor, introducing European cultural fashions into China, as well as Chinese ideas into Europe. Ricci translated Christian terms into Chinese, wrote books in Chinese and initiated the modern Chinese cartography; Castiglione portrayed the emperors KangXi and Qianlong and built an Italian style pavilion in the Forbidden City; Bouvet illustrated to Louis XIV and his advisor De Quesnais the political and economic ideas of the Chinese.
The description of China made by Jesuits was so impressive, that Voltaire, and especially Leibniz, expressed the idea that Europe should have been unified, like China, into a sole large kingdom. Leibniz was so fond of Chinese culture, that he suggested, in his work “Novissima Sinica” (“The Latest News from China”) that not only Europeans should have sent missionaries to China, but also Chinese should have sent their own to Europe.
Jesuits helped also the Chinese empire to arrive at an agreement with the Russian (the Nerchinsk Treaty). In Novissima Sinica, Leibniz, who had met Peter the Great in St.Petersburg, expressed the hope that the new Russia could have constituted a bridge between Europe and China.
The ancient relationships between Europe and China thanks to Catholic missionaries are still vivid on the background of the discussions under way for stabilising the relationships between the Catholic Church and China.