I wasn't suggesting that Paul was influenced by the Upanishads, but that there is a general vague similarity between Upanishadic thinking (internal religious experience is as good as, if not better than, ritual sacrifice) and Buddhism (the right mindset leads to liberation) and Pauline Christianity (faith produces salvation), in that they all privilege the internal spiritual experience over public religious rituals, at least in theory. They also differ from earlier religions in what they propose as a goal: salvation, as opposed to a good harvest, protection from earthquakes, success in battle, etc. The focus is on the life to come (or in the case of Buddhism, the lack of a life to come).In particular, Paul's concept that "salvation" from eternal torment is to be achieved by having correct belief (unaccompanied by anything else) was, I think, something absolutely novel and in the first century, and greatly innovative as a religious paradigm. Though the Upanishads may have represented an evolution from Vedic thought within Hinduism, the western religions developed independently of their Eastern counterparts, with no apparent influence in either direction. The Pauline religious paradigm cannot be thought to have been influenced by Eastern thought. I say that Paul's paradigm was only fully realized during the Reformation, because it is only in the less traditional Protestant churches (the further from Catholicism the more this is true) where in the assertion is made that one is "saved by faith (belief) and not by works (practice)".
I would not consider Plato to have been active as a religious innovator. Your suggestion of the Buddha is prescient, but entails an essential difference from the Pauline model: for the Buddhist, correct thinking (close enough to correct belief) is a means to human liberation from suffering in this life, but (and I do not speak authoritatively here) as a means to eternal salvation, is it?
Most Protestants would certainly agree with this statement, but I doubt very much that Luther and those who came after him understood what Paul said in the same way that Paul's contemporaries might have. Luther took the words of Paul in light of his anxieties about contemporary Catholic practice, and it would be quite easy to contrast justification by faith alone with the complicated apparatus of late Medieval Catholic practice, but Paul didn't have that in mind when he wrote, because it didn't exist. Paul was more concerned with drawing a line between the Mosaic Law and faith in Christ. Was Paul making a general statement about faith versus works? Or was he specifically contrasting faith in Christ with adhering to the Jewish law? A lot of contemporary scholarship has shown that parts of the New Testament were directed at specific controversies of early Christianity, but subsequent generations (of whatever denomination) have taken them to be universal truths separate from their original context. (This is true of the Hebrew scriptures as well, but we're speaking of Paul).I say that Paul's paradigm was only fully realized during the Reformation, because it is only in the less traditional Protestant churches (the further from Catholicism the more this is true) where in the assertion is made that one is "saved by faith (belief) and not by works (practice)".
grātiās! sed magnum nōn est; exercendō (et facilius loquitur dē philosophiā, quia nōn tam multīs dīversīsque verbīs opus est...)Your Latin is great, man! I wish I could do that; it would take me ten minutes just to express "In my view," properly. I am quite impressed. (BTW, mi is an unusual dative form here?)