I thought I’d go over what I feel the evidence for Jesus’ historical existence is. I’ve tried to look at the evidence in a non-biased manner, so do not be surprised if what I suggest is not entirely in line with traditional Christian teachings.
Josephus (37 CE - 100 CE) is one of the few historians contemporary to Jesus who would have any interest in reporting about Jewish messianic claimants from Judea, If Jesus was a real person, we would therefore expect Josephus to mention him, and as it happens, despite all mythicist claims to the contrary, he does.
Josephus, in Antiquities XX.9.1 mentions:
“Festus was now dead, and Albinus was but upon the road; so (the High Priest) assembled the Sanhedrin of judges, and brought before them the brother of Jesus, who was called Messiah, whose name was James, and some others; and when he had formed an accusation against them as breakers of the law, he delivered them to be stoned.”
A clear reference to a figure with more than a few similarities to the Jesus of the New Testament. Some Mythicists will tell you that the Jesus in question was ‘Jesus Ben Damneus’, a Jewish High Priest. The problem with this hypothesis is that Josephus was very clear to distinguish between people of the same name, if Josephus meant to say ‘Jesus Ben Damneus’ he would have said so, especially since he later mentions Ben Damneus in the same passage. So this Jesus must have been unique, with ‘the messiah’ being what he was primarily known as. This character has more than a few similarities with the Jesus of the New Testament, Other mythicists will claim this is an interpolation by later Christians. This is highly unlikely however, since the Church father Origen quoted from this passage far to early in Christian history for Christians to have been in the power to tamper with texts.
Earlier, Josephus is even clearer in Antiquities XVIII.3.4:
“Now there was about this time Jesus, a wise man, if it be lawful to call him a man; for he was a doer of paradoxical deeds, a teacher of such men as receive the truth with pleasure. He drew over to him both many of the Jews and many of the Gentiles. He was [the] Christ And when Pilate at the suggestion of the principal men amongst us, had condemned him to the cross, those that loved him at the first did not forsake him; for he appeared to them alive again the third day; as the divine prophets had foretold these and ten thousand other wonderful things concerning him. And the tribe of Christians, so named from him, are not extinct at this day.”
Mythicists are quick to insist that this whole passage is a forgery. Here they go against the great consensus of Josephan Scholars (mostly Jews, who lack a dog in the fight). True, whilst we can safely say that at least some of this is a later interpolation, it is unlikely that as devout a Jew as Josephus would have accepted Jesus as the messiah without skepticism, there are hints that there is some authentic Josephan material contained here. The passage contains language which Josephus frequently uses elsewhere, which is absent from early christian texts. Furthermore, early paraphrases of this passage seem to show Josephus having more skepticism of the claims of Jesus, exactly what we would expect from him, and lacking the editing of the Christian Interpolator. This clearly shows that the Interpolaters were editing something already in existence, rather than making up the passage on the spot. There is no reason to deny the authenticity of the original text, especially since it accurately describes what a 1st century devout Jew would have thought about Jesus.
The Birth of Jesus:
All but the most conservative scholars accept the accounts of the nativity in Luke and Matthew to be contradictory and ahistorical. It is highly unlikely for example that the Romans would have recalled Mary and Joseph to the home town of an ancestor so far distant as King David. Jesus was known to be ‘from’ Nazareth, so inventing a story about his birth in Bethlehem was likely an attempt to shoehorn his birth into Biblical prophecy (Micah 5:2). Some mythicists use this as evidence for their case. Yet one must ask why would the gospel writers have gone through this trouble in the first place? The most obvious answer is that it was well known that Jesus came from Nazareth in real life, and this fact was embarrassing to early Christians, since the expectation was that the Messiah would be born in Bethlehem. Furthermore, if Jesus was a fictional character, why would such a small, insignificant town such as Nazareth be in the story at all?
Lack of mention of Jesus mythicism in early Anti-Christian polemics:
A Messiah who never existed would be a great argument to be used by Pagan and Jewish critics of Christianity. The fact that they never used this argument suggests to us that there really was no doubt that he existed in the centuries after his death.
Lack of mention of Jesus mythicism by early Christians
Contrary to the claims of some Jesus mythicists, the Epistles of Paul do not describe Jesus as a purely divine, heavenly being. According to Galatians 4:4, for example, Jesus was born of a woman, not only is this an indication that Jesus had a human, not divine nature, but it was a common Jewish expression that someone was human. This heavily implies that Jesus was according to Paul, human, not what we would expect from a purely heavenly being. Furthermore, divine heavenly beings tend to be immortal, so how Jesus could have been executed, (1 Corinthians 2:8) and buried (1 Corinthians 15:3-4) is unknown. Paul also claimed to have met Jesus’ brother James, and makes no mention of him having a divine heavenly nature. (Galatians 1:19) This shows that the earliest Christian texts understood Jesus as being an earthly, human being, not (just) a divine one.
Yet the possibility of Jesus being a purely divine, heavenly being would have been perfect for Gnostics, who shunned the physical and embraced the spiritual, and emphasised the spiritual aspects of Christ over his physical aspects. Yet even they described him as appearing on earth (albeit as a spiritual being, with the illusion of flesh), which indicates that the fact that Jesus (not just Christ) actually existed could not be denied even by those whom it presumably would have been convenient to.
A particularly interesting source of the historicity of Jesus is the early church father Papias. Papias wrote Expositions of the Sayings of the Lord, a text containing sayings of Jesus, which do not show any reliance from the gospels, or other early christian texts. Rather, Papias claimed to have known the apostles of Jesus himself, or at least to have known those who knew him. This is as close as we have to an eyewitness account that Christ was a real person, as Bart Ehrman says, as Papias was able to source quotations by Christ from those who knew him.
On mythicist arguments
Finally, Jesus mythicist arguments tend to offer highly weak explanations for how a mythic Jesus could have arose. I we use the principle of Occam’s reason, this likely means that the simplest option, is that Jesus was most likely a real person.
Jesus was a Jewish incarnation of dying and rising God myths
To start with, there is very meager evidence for such a belief. the God Osiris, was killed, and reanimated, but remained dead, in the underworld. The Babylonian God Tammuz is sometimes mentioned, he was indeed but considering how Second Temple Jewish texts were highly polemical ‘against’ Babylonian paganism, (for example) this is quite simply absurd. His death and resurrection is furthermore very different from that of Jesus, as every half a year he returns to the underworld, then comes back.
But even if there was such a belief as a dying and rising god, this is highly unlikely to have been the basis for the Jesus Christ. The evidence suggests that the earliest Christians did not believe that Jesus was divine, or at least this was not the universal position, which you would expect it would be if the very foundation for Jesus was a god. This is shown both in biblical and extra-biblical texts. According to Pliny the Younger, Christians sang hymns to Christ ‘as to’ a God, not ‘as’ a God.
Jesus was an amalgamation of various pagan gods, or a pagan god adopted by early christians
A similar hypothesis, but rather than claiming that the basis for Jesus was a Jewish incarnation of a possible belief, this theory suggests that multiple non-Jewish pagan gods were the basis for the figure of Christ. This theory has no academic acceptance even by mainstream mythicists such as Richard Carrier and G.A.Wells, largely being the domain of sensationalist authors such as Dorothy Murdock and Freke and Gandy, conspiracy theorists such as Peter Joseph and gullible online New Atheists. Gods often mentioned include Horus, Mithras, Dionysus. Krishna and the Buddha. To start with, many of thees parallels are either weak, or nonexistent, many of them exist, but can be explained by pre-existent Jewish traditions as well (such as the virgin birth) and many of them postdate the foundation of Christianity. But the reason why this theory can be safely ignored is due to the fact that it is an absurd premise that highly Anti-pagan first century Jews (who, for example cut their hair short because long hair was considered pagan) would steal pagan ideas as the basis for their messiah. In fact, early Christians went through the trouble of trying to accommodate gentiles into their new religion, strange considering how Christianity is said to have a pagan foundation!
Jesus was a heavenly/celestial figure who was not considered earthly until later
The position taken by Earl Doherty and Richard Carrier. As we have already discussed, contrary to this claim, the Pauline Epistles, the earliest Christian texts ‘do’ mention Jesus as an earthly, human figure. Furthermore, Doherty offers no evidence for the existence of a ‘sub lunar realm’ where divine beings can appear in the flesh in Platonic philosophy, which is the cornerstone for his argument.
I hope you enjoyed.
My main sources were:
Did Jesus Exist?, a blog post by Tim O’Neill.
Did Jeus Exist?: The Historical Argument For Jesus of Nazareth, by Bart Ehrman.