Among other things: the little story of the "widows' mite" or the "penny" she gives to the church, apparent finds an exact predecessor in Eastern lit. Rather as the stories of Noah and Daniel do as well, from the Old Testament.
More importantly, the major ideas attributed to the Buddha, fl. 500 BCE, seem quite like Christianity. Buddha is the son of a king or lord, he renounces the earthly throne, to live in poverty; and to speak of the renunciation of our "desires," as the way to a higher state.
The Anthropological study of cross-cultural diffusion of ideas, combines with the study of Comparative Religions, in fascinating ways. With the Buddha 550 years before Jesus, there would have been plenty of time for Eastern, Buddhist influences, to travel now and then to Jerusalem.
Generally I favor the thesis that Christianity represents largely, a kind of Greco-Roman Hellenization of Judaism; especially you can see quotes of Plato specifically, in Paul; Plato's theory of forms; the idea that things here on "earth" are just a pale "shadow" or imperfect "copy" of the ideal "forms" or "patterns" in "heaven."
But there is no doubt that a general impoverished, spiritual, "priestly" ethos, existed well before Jesus, all over the East. And likely influenced some in Jerusalem, and communities more northern (Galilee being closer to "the East"
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