Finally I have my answer for this saved! So here is a copypasta of mine from another thread...
So there is a lot of potential for this OTL, one example being somewhat apocryphal and the other kind of weird in it's non acceptance otl.
For the apocryphal version, there is a largely spread story that the Christian missionaries to the germanic peoples told them that their own mythology was actually the past world, our world being post ragnorok and Baldr being Yahweh/Jesus with the bible as this world's story.
Ive found a few references to this in history books, but when I follow the references it always seems to come to a dead end. So take that with a pinch of salt.
I am somewhat inclined to think that this might have happened based on two premises.
Firstly, it explains some of the christian themes present in the eddas and the portrayal of Baldr as somewhat christlike in a culture which didn't really have the same significance placed on such narritives.
The other is the existence of the second example.
Otl, anyone familiar with the Irish Book of Invasions will note a rather interesting trend of Christian syncretism. As many cultures did, they tried to integrate Christianity into Irish history, the earliest tribe of ireland being another group of Ark survivors, a later tribe being another escaped group in the exodus and later the gods themselves converting to Christianity.
Curiously for an attempt to Christianise Irish mythology, it actually promotes a radically different theology. Yahweh of course is real, but so too is the Goddess Danu in a fashion weirdly reminiscent of later Wicca.
It is worth noting that even to this day, a lot of devout Christians have accepted the book of invasions and the Annals that reference them, the aristocratic side of my heritage tracing their way back to the god Lugh. I imagine with no centralisation, another Abrahamic faith that is literally half pagan could be based in Ireland.
While this is interesting, I did specify in the OP that I was looking to syncretize Christianity with a form of Mediterranean polytheism. Sabaziism, Isiacism, or even further with Neoplatonism, perhaps.
Now, I’ve been thinking about this over the course of the last few days, and first of all I am not convinced that Jesus was a Zealot. Many of the threads I have seen on the discussion of Jesus avoiding crucifixion talk about his movement taking on a more militaristic nature, and the more recent threads base this off of Reza Aslan’s book, which I have read, and I found a number of aspects of to be highly questionable. My thoughts on the matter are much more in line with the idea that Jesus was a mystic healer, perhaps a sort of proto-Hasid, but who was quite clearly more focused on disputes within Second Temple Judaism, especially with the Pharisaic Movement, than outside of it, i.e., Rome.
Secondly, discussions on if he were to have children or not on here tend to be very milquetoast, claiming that very little would change. Anyone with children knows that’s hogwash. Jesus would likely be considerably more careful in terms of what he preached and where he preached it if he had children, or at the very least he likely would not have gone so willingly when the Pharisees’ men came for him at the Garden of Gethsemane (if any of that story is to be believed in the first place).
If Jesus had married and had children, would he have brought them with him on his missions? Sending money back home to Nazareth is hard, but bringing them along is potentially dangerous. Mary was apparently in Jerusalem with him at the time of his crucifixion however, so I think it’s possible that he would, but only if he had some way to guarantee their security. So, rather than just his apostles, Jesus is likely to surround himself with a security detail, and his family as well. Wherever he is staying probably has followers camped outside it, and he has more than just Peter and John with him at the Garden.
Perhaps in this instance, Judas doesn’t even need to betray Jesus because it’s no secret where he is, as every time he goes somewhere he has something of an entourage. That in and of itself changes the narrative considerably, doesn’t it? So let’s say instead, when the Pharisees come for Jesus at the Garden of Gethsemane. Peter and John are with Jesus along with some more followers, and Judas is back with his family. Jesus’ followers put up a more considerable fight and Jesus, John, and Peter get away. Judas is back at the safe house, and dies trying to defend Jesus’ family. Jesus’ son, let’s call him Elijah (probably around 4-5) escapes, but his mother is captured and hauled off in the middle of the night before the Pharisees, who accuse her and her husband of witchcraft and idolatry in the Egyptian fashion and conjuring devils and demons.
Meanwhile, Jesus attempts to rally his followers to bring them to the Temple to force the Pharisees either to hand her over or to halt the proceedings until a less stacked court can be assembled. The Pharisees aren’t stupid, and so they have a very large security detail of their own that is prepared to fight Jesus’ followers if need be. However, Jesus and the Pharisees’ men are knocking on doors and getting people out of bed simultaneously, some of whom are neighbors, and so the whole thing turns violent pretty fast as followers of Jesus attempt to physically bar their neighbors from attending the proceedings and are killed by the Pharisees’ men.
Pontius Pilate is woken up in the middle of the night by the whole affair. Where do we go from here? We know that the OTL Pilate was something of a sadist, so does he just side with the establishment and take the opportunity to not only have Jesus killed, but wipe out his movement in Jerusalem? He ruthlessly massacred the Samaritans IOTL, but I think it’s worth noting that the Samaritans were concentrated outside of Jerusalem, where he slept. He may want to try and diffuse the situation for his own safety. There are two ways to do this - either allow Jesus and his followers into the proceedings (Jesus will be arrested and tried alongside his wife, but the court is less stacked), or halt the proceedings until morning and allow them to proceed then.
If Jesus and followers are allowed in, what happens next? I’m skeptical as to whether they would be executed because there would be a more even debate going on. Are they exiled? If so, would Jesus preach to gentiles en masse the way Paul did, or is that something that was specifically Paul’s invention? If they are not allowed in and the proceedings are halted till morning, does Jesus submit himself to arrest to stop the bloodshed? How does this affect the nature of the proceedings? According to the gospel narrative, the Pharisees convicted him in the middle of the night and brought him before Pilate the next morning. Jesus’ followers were never assembled. If the trial has to wait, there is probably going to be a large mob waiting outside, and this could still very well influence the outcome.
If Jesus and his wife are exiled, then where do they go? Egypt? Egypt has a sizable Hellenistic Jewish community and its own temple at Leontopolis that would likely be very receptive to his teachings. Alexandria is a hotbed of Greek philosophy and various polytheistic mystery cults that could influence him and/or his followers or his son, especially after his death. The equation of Jesus with Horus isn’t that much of stretch, I don’t think. One could say that Mary was a living manifestation of Isis (something that was well within the realm of possibilities, as various Ptolemaic queens had been recognized as such in the past) impregnated through immaculate conception by Serapis with the Christ/Horus child. As Jesus and his teachings were definitely within the scope of contemporary Second Temple Judaism, I highly doubt Jesus would make such a connection himself, but a prolonged ministry in Alexandria coupled with syncretization of Hellenistic philosophical concepts a la Pauline Christianity could possibly result in a sect of gentile converts making this connection... if he ministers to gentiles, which is a big if. If this were to happen however, would this gentile sect have a problem making sacrifices to the emperor?
Mind you, the imperial cult was not set in stone at this point in time either. If I remember correctly, it was suspended during the Flavian dynasty, and so a minor blip in Roman politics could see this suspension continue. If this happens, then a syncretized Christianity that preaches that Jesus was a living manifestation of Horus as per immaculate conception of his mother Mary by Serapis whose kingdom is not a literal political entity but rather a religion poses no thread to the established political order.
He may also head north to Syria/Cilicia however, where he might come into contact with Paul directly, a much younger, perhaps more malleable Paul, and... if we really want the “stars to align”, Apollonius of Tyana. An interaction (not necessarily collaboration) between these three could be VERY interesting.
But then, we can also have Jesus and his wife executed, with rumors of their resurrection as a couple rather than just him spreading afterward among a following that is being violently repressed in Judea and may flee in various directions from the start.