Calebin F, your argument from a Jewish perspective for Jesus as a real human is: Why would Responsa (formalised rabbinic replies) develop antithetically to a non-existent person? Superficially a fair point but not necessarily valid. I suggest that the body of sacred Jewish writings, however revered, is itself inherently the product of politico-religious and nationalistic bluster and myth in the first place. In other words a system of beliefs not founded on fact but from mainly non-existing i.e. fictional characters such as Moses and the twelve sons of Israel. (All have precedents in earlier exotic tales mainly from Egypt). Therefore the credibility of Jewish pronouncements on other heroic figures is suspect. It is easier to diminish the importance of an individual than it is to suppress a myth. All religion, since it is mostly devoid of testable evidence; is just propaganda. Religious argument therefore, to put it crudely, it is a case of “My myth is better than your myth.” If human evolution is true but not readily observable, then the evolution of ideas and mythology is more readily accessible to the textual scholar. To disentangle deeply entrenched and strongly felt beliefs, require research into the facts and not just repeating suppositions...as you are well aware.
The God-men tales of the near East and western Asia was the template for the “christ stories” of which Jesus was the last one of note. The reason for his prominence being that this character was promoted by the Roman state and through the agency of its Catholic Church; left a legacy of dominant small O orthodoxy of ‘Christ belief’ right up until today. However prior to the fourth century we have a string of heroic messianic celebrities supplying the answer to the greatest existential problem facing humanity; how to overcome death. It was a preponderantly illiterate world, the transmission of belief outside of the temples and synagogues would have been for millennia; through passion plays. They still exist today, even in my nearest village in civilised and literate England, the nativity is re-enacted on Christmas Eve every year. Joseph and a Mary (played by the last couple to be married at the local church) travel round the village with Mary riding a donkey, and knocking on doors looking for a place to stay, rejected, they stay at a barn at the manor house replete with oxen and a baby Jesus in a straw filled manger.
A mordant is the chemistry which fixes colour in the process of dying cloth... for the illiterate throughout history; the nativity play or any such play as the Passion of Christ would surely be the ‘mordant’ to fix a “belief” into the cultural fabric. (It is also a strong clue as to the how and why, many of the Bible stories came to be recorded... they are transcripts of folk plays).
So if you believe that Jesus existed as a breathing human, why not believe the pedigree of his literary forebears: the fictional crucified Dionysus who had the same history attributed to him, why not the mythical Osiris, born of a virgin (Meri) whose step father was Sep, born in a cave with oxen, who had twelve disciples, walked on water, preached, healed the sick, cured leprosy and resurrected his friend Lazarus (El Osiris)... a thousand years before Jesus?
The character or role of the God-man and its story-line was well established in the peasant consciousness. This belief was retained without critical thought, with minimum education other than a religious tradition, and maximum gullibility. The God-man hero existed independently of a personal name of the lead character; it had already done the rounds for many centuries before the first century. He was the son of the Sun God he was the saviour of mankind, the Christ. The Jewish authorities would have needed to challenge the belief adopted by some of its number in joining a Christ –cult. They would not investigate whether he existed, since the unbelievably exciting message of the magic belief was that “the word had been made flesh” and many Jews had declared this as it was the founding cry of Jesus- Christianity and axiomatically held to be true. The Jews would have fought against the belief and the implication of losing power to the new cult and not the facts of the case.
So I suggest that the Jewish stance was to decry the Christ cults with a mythical founder who had a Jewish sounding name called “Jesus”. A man unknown to any credible historical source although conflated with other Jesuses over time. We are in the territory of folk myth, gullibility and messianic hope...not reality.
Osiris was not real neither was Dionysus: why should anyone else sharing the same fictional characteristics attributed to him have been a live person? That he could have existed is not germane to the foregoing and is a misleading sentiment.