The spread of Jewish communities in Asia can be seen as part of a wider phenomenon of movements of people, cultural influences, and cultural exchanges in the vast regions between the Greco-Roman world, the Near East, Iran, and Central Asia. The eastern border of the Roman Empire was only a political frontier, for the peoples living under Parthian and later Sassanid rule shared many religious ideas and traditions with, for instance, the indigenous inhabitants of Roman Syria and eastern Asia Minor. Just as Judaism had attracted non-Jewish adherents in the Roman Empire, it likewise found sympathy and, doubtless, converts in Asia, while it also influenced other religions, giving birth to sometimes remarkable religious hybrids, for example, the Mandaeans in the south of present-day Iraq. Likewise, Christian groups would spread in the wake of Jewish communities far to the east. At the same time, the lands east of the Roman Empire in the first centuries AD experienced a strong religious revival. Thus, in Iran the traditional religion of Zoroastrianism with its fire worship and eschatological message (i. e., about the end of the world and the final rewards and punishments of humankind) re-emerged under the Sassanids, even to become the state religion. This renewed Zoroastrianism, with its sharp distinction between good and evil, light and darkness, God and Satan, made strong ethical demands of its followers and became more and more intolerant and exclusive. Its revival under the Sassanid kings was not unrelated to their aggressive policies toward Rome and the intermittent suppression of religious minorities within Iran.
Farther into Asia, Buddhism in this period flourished and steadily expanded. In the Hellenistic age, the area of northern Pakistan and modern-day Afghanistan had become a stronghold of Buddhism, from where in the first centuries AD it spread along the Silk Road into China. By that time, the main branch of Buddhism here had become the Mahayana (“the great vehicle”) that in some important ways distinguished itself from the older, so-called Hinayana (“the small vehicle”) or Theravada (“the old faith”) Buddhism, in that it stressed far less the rigorous asceticism of the individual as a path to salvation—for in that way, real salvation or enlightenment could only be attained by a very small group of steadfast ascetics. Instead, it preached a message of possible salvation for the mass of the common people with the help of the Buddha in his various divine manifestations and of the bodhisattvas, those altruistic spirits who had voluntarily postponed their own ultimate salvation in order to assist, with the spiritual merit they had themselves already assembled, all those poor souls who needed help and mercy. These bodhisattvas and Buddha manifestations formed a veritable pantheon of Buddhist “deities,” and sometimes local deities would be admitted to it as new bodhisattvas. This was the form of Buddhism that in the 2nd century AD reached China and in the 6th century Japan. It was as the message of Buddha’s compassion with suffering humankind that this Mahayana Buddhism
Acquired a large following, while the older form was more or less preserved in Sri Lanka (from where it would be dispersed to Southeast Asia in the 10th century).
There are some remarkable parallels between Mahayana Buddhism on the one hand and some religious movements in the Greco-Roman world on the other, especially in a shared longing for redemption or salvation from an earthly existence that was seen as fundamentally miserable, and in the concomitant worship of a divine Savior or Redeemer who from sheer goodness and compassion concerned Himself with the fate of humankind. Thus, there are some obvious similarities with early Christianity as well. There is, however, no reason to think of any influence from one on the other beyond the possibility of some stories and story-motives traveling from east to west, and perhaps vice versa. Rather, the similarities seem to point to an underlying pattern, a religious need for personal salvation, that in this form could come to the surface after many traditional sociopolitical and religious links and associations had been severed by the establishment of large multi-ethnic and multinational states and empires in the wake of Alexander’s conquests.
Western Asia and Iran in the time of the Roman Empire constituted a region in which perhaps the most numerous and the most diverse religious movements ever came into contact with each other. Besides the numerous and ancient local cults and the national religion of Iran that Zoroastrianism had become, there was a Buddhist presence in the east of Iran, there were many Jewish communities and syncretistic groups such as the Mandaeans already referred to, and since the 2nd century also Christian communities. In this environment in the 3rd century AD, a new, syncretistic world religion appeared, constructed from elements of all the aforementioned religious movements. This was Manichaenism, named after its founder Mani. He was a visionary preacher and religious organizer who was expelled from the Jewish sect to which his parents in Mesopotamia belonged for his claim of having received special revelations ordering him to preach as an apostle of Christ a completely new message. He presented himself as the last in a line of historical prophets or apostles—among whom he included Zoroaster, Buddha, and Christ—who had come to save humankind. His religion was extremely dualistic, teaching a sharp division between light and darkness, good and evil, in the Zoroastrian tradition. The human soul was originally part of the world of pure light among the stars and had as a result of an extremely complicated sequence of fateful events become imprisoned in human bodies, just as other particles of the divine light had been swallowed up by plants. Only by an extremely ascetic life, practicing celibacy and vegetarianism, could an elite among the faithful—the elect—hope after death to return to the realm of light. Other believers, who had to maintain the elect in this life, could hope to be reborn among the elect and thus in a following generation be redeemed themselves. All others, the unbelievers constituting the rest of humanity, were doomed: they would in the end, when good and evil, light and darkness, would be forever separated, burn to nothingness together with the material world. Mani modeled his movement after the Christian Church and sent out 12 apostles to various regions. He had much success and Manichaean communities sprang up in the Roman Empire, Iran, and Central Asia. There, it was the second missionary religion, after Buddhism, that spread along the Silk Road and in the early Middle Ages even reached China. Mani’s creation thus became a truly universal religion. But it provoked resistance too, mainly because of its radical asceticism and rejection of the existing order. In Iran,
Already in the 3rd century the Manichaeans were persecuted (Mani himself died in prison), and in around 300 the Roman emperor Diocletian outlawed them under punishment of being condemned to the stake. The Christian emperors of the 4th century and later continued that policy, with the result that in the 6th century the Manichaeans practically disappeared from the west, although some later Christian heretical movements probably continued in their footsteps. In Central Asia, they vanished as a result of the expansion of Islam in the Middle Ages; only in China they would linger on until about the 16th century.