You would likely never have heard of Christianity or Jesus without Paul's missionary work to the Gentile communities, or without Constantine deciding to give the Empire's blessing to a minor and fairly obscure religion.
Without Paul and Constantine, Christianity might well have remained an obscure and tiny sect of Judaism and might have faded away with time.
That is what I meant that in the context of history, Jesus would never have been of profound historical influence without Paul and Constantine, and the events surrounding them over the course of three centuries.
Actually it would have been spread the same way Paul spread it, by converted Pharisees traveling from synagogue to synagogue and preaching to the congregations and crowds. Jesus had been preaching for three years before going to Jerusalem, and most likely his followers had already been spreading his speeches, or sermons and word of his healings or whatever you want to call them. He was not a 'poor obscure peasant', but from a family descended from the line of David, and while a 'carpenter', Joseph was not a poor one, but held a franchise to supply wood to the Temple, which would have been a lucrative business indeed given the priests made a lot of money sacrificing animals for the streams of pilgrims and selling the cooked meat. All those letters came from established congregations, over significant distances around the Empire, not just a couple of people here and there. Paul wasn't the only Pharisee to convert; both Mathew and John were probably Pharisees as well, or taught by them, given their extensive knowledge of the Torah, as was Jesus's obvious scholarship. Luke was a gentile, but he was a follower and student of Paul, who was also likely a student of Gameliel the Elder, and Jesus's comments on the Torah indicate he might have been a student of Hillel's school.
Christianity was already huge by the time of Constantine; it had been through recent severe persecutions by the other Consuls of the Tetrarchy and severe one under the previous Emperor as well; commentators remarked on how crippled up many of the attendees at Nicea were, having been tortured and abused, saying it looked more like a convention of beggars than theologians and Bishops. The reason Constantine was impressed by them was precisely because their social programs for their churches and congregations were so successful compared to the pagans' corrupted scams and the Imperial bureaucrats' woefully inadequate efforts, and he put them in charge; not a big mystery at all. Constantine changed nothing, and 'rewrote' nothing, and neither did the Council attendees; that's because the orthodoxy was dominant from the beginning, and most of the oral witnessing already established before the fall of the Temple in 70 A.D., and well known for some 300 years already. If they had changed it all up they would have been laughed out of their own houses for being stupid.
It survived because it was so obviously humanitarian and universal a social paradigm it stood head and shoulders above the state religions and bloody atavistic pagan rubbish its popularity could withstand even the extreme persecutions the Roman govt. could impose on it, and also the same in the Persian regions and in the Celtic regions of Europe. In the 'context of history' it was pretty successful, and a far better alternative than the other options, and the same goes for most of 'The Other Options' today as well.
