The point of the presumed earliest Gospel, the Gospel of Mark, was not to highlight the ministry of an eccentric 1st century Judean rabbi; rather, it was to demonstrate the power of the Spirit which descended onto Jesus in the form of a dove after he was baptized.
When we isolate the earliest Christian sects, which in my mind were the Ebionites, Cerinthians, and Carpocratians (AH i.25-26), we see, despite significant theological differences, they all centered around this theme – the Spirit descended onto Jesus. It had not been with him for his entire life, as the canonical Gospels of Matthew and Luke would imply. The Spirit encapsulation was a new and temporary phenomenon in Jesus’s life.
The fact that these groups all used scaled-down versions of the Gospel of Matthew (ie a Proto-Synoptic Gospel), which lacked the virgin birth and resurrection, makes it even more clear that the focal point of the story was the baptism, and the powers it afforded Jesus. This proto-synoptic Gospel probably resembled Mark as much as it did Matthew; when you compare church father Irenaeus’s characterization of Cerinthus in Against Heresies i.26.1 and his description about what sort of people were using the Gospel of Mark in AH iii.11.7, the theologies seem like an exact match. It was later church fathers, notably Epiphanius, who made the explicit case that Cerinthus used Matthew, making Cerinthus parallel to Paul’s Cephas in Galatians – a wrong-headed follower of James who came to reject the practice of eating with the uncircumcised. According to Epiphanius, it was Cerinthus who looked to be an exact match to Paul’s version of Cephas when he opposed Peter’s eating with the uncircumcised in Acts 11:1-3.
Jesus’s ordinary nature could not have been more clear than in Mark 3:21, when Jesus’s family considered locking him up because they thought he was out of his mind for casting out demons.
The big question, which I suppose will never be answered satisfactorily in the mainstream is this: given that the focal point of the earliest Synoptic Gospel was the Spirit, rather than the attributes of the man who encapsulated the Spirit, doesn’t it make more sense that the man in the story was simply a metaphor for any Christian who received the Spirit via baptism? Rather than a specific person who was active in the 30s?
There is an old saying: Jesus was either lord, liar, or lunatic. Of course, this is faulty logic in the form of a false choice. A more reasonable option is that Jesus was a legend. The fact that Christianity’s earliest origins seem to have been as a mystery religion (Paul and Justin Martyr explicitly say so) should make us hesitant to believe any of the earliest Christians, because the main point of a mystery religion was to hide or obfuscate internal workings from the outside world.
As the saying goes, there is often some truth hiding in deception. But does that mean Jesus Christ existed?
Given what seems an almost slavish dependence on the works of Josephus (notably Mark’s references to Theudas, the Egyptian, and Jesus ben Ananias), coupled with the fact that many stories in the Gospel are re-tellings of Old Testament (Septuagint) stories, I am inclined to think that Jesus was a composite of a variety of Judean leaders, including the most obvious ones in Josephus’s history, and was constructed by Diaspora Nasarene Jews, who were concerned about restoring the version of Judaism (keeping the old way) which was a fixture in Solomon’s temple, and which would have included incense burning, bread making, and wine consumption for the Queen of Heaven.
Why the virgin birth?
There was a schism between Diaspora and Judean Nasarenes at the time the Nasar were evolving into Christians. One of the rifts was between the Paulinists and the Jamesians.
Revelation 12 was probably the core of the Nasarene philosophy (along with 2 Esdras 9-10). The point of it was that the Queen of Heaven, the celestial mother of all Nasarenes (Rev 12:17), gives birth to a male Spirit, and it would be that male Spirit’s manifestation on Earth which would restore the Queen to the temple. Any Christian would have been the brother or sister of any other Christian because they were all sons and daughters of the most high and the Queen of Heaven.
The earliest James followers, presumably the Ebionites, did not believe in the virgin birth. Yet Paul claimed to have been born from a miscarriage (1 Corin 15:8), which matched a prophesy in the Gospel of Thomas, which told the disciples to be on a lookout for one not born of a woman, despite being told earlier to follow James.
It was the Nazarenes, who resembled the Ebionites, except they believed in the virgin birth and resurrection, who used an altered version of the Gospel of Matthew which contained the virgin birth – this Nazarene Gospel probably looked very similar to extant Matthew.
Matthew’s virgin birth has correlation with the Infancy Gospel of James; again, James is key. My speculation is that it was James’s followers, the later Ebionites (who the earliest versions believed was the true recipient of the Christ Spirit) who injected the virgin birth into their tradition. Given the fact that there was increasing hostility between the Paulinists and the Jamesians, as evidenced in Galatians, the Epistle of James, The Shepherd of Hermas, The Gospel of Matthew [as contrasted with Mark and Paul’s Epistles], and others, there was probably a political need to hijack and rewrite various traditions to highlight preferred historical leaders, and to demote adversaries.
This would also explain the mid-2nd century’s increasing polemics against those who did not believe Jesus came to earth “in the flesh”, found notably in Polycarp’s epistle, the Pastorals, Tertullian, and other Heresiologists. I believe this phantom spirit characterization of the Docetists, by the emerging Catholic pre-Orthodoxy, was at least partially a mischaracterization. Rather, I believe the victims of the Heresiologists’ attacks, notably Marcion, probably had views which matched Elxai, a leader of Ebionites, Nazarenes, and Nasarenes, who believed the Mother Spirit and Christ-Spirit were 96 mile tall figures in the sky, and the transference of those Spirits into humans was an invisible process preceded by baptism.