Any Historical Sources That Dispute The Existence Of Jesus?

[Zavdiel]

1John 4:1-3
1 Dear friends, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world. 2 This is how you can recognize the Spirit of God: Every spirit that acknowledges that Jesus Christ has come in the flesh is from God, 3 but every spirit that does not acknowledge Jesus is not from God. This is the spirit of the antichrist, which you have heard is coming and even now is already in the world. [My italics.]

2John 1:7
I say this because many deceivers, who do not acknowledge Jesus Christ as coming in the flesh, have gone out into the world. Any such person is the deceiver and the antichrist.

The fact that there were many Christians who thought of Jesus as a spiritual apparition rather than as a real flesh-and-blood person is attested by the fact that refuting this position required not just one canonical letter but two.

What I find really interesting about these passages is they implore the reader to believe that Jesus was a flesh and blood person not based on recent history but on faith.

You interpret these passages as if they were written to Docetists in order to persuade them to believe that Jesus "came in the flesh". But rather the context makes clear that John is giving instructions to those who already believe this (cf. 1 John 4:1 and 2 John 1-3). He is not arguing that Jesus came in the flesh at all (either "by faith" or historically) because his readers already believe it. Indeed, if this John is the same John who wrote John's gospel, then he has written a whole book against Docetism by appealing to eyewitnesses. Whether or not John's gospel was written down before these letters, John 1:1-3 is direct evidence that John testified publicly on the basis of what he had heard, seen, looked at and touched with his hands.

So, all these references attest to is the existence of Docetism in the first (?) century. But Docetism is the belief Jesus appeared to be a material person, while he was actually an "immaterial" one. Now, what best accounts for this belief, even considered alone: the existence or the non-existence of Jesus? A non-existent Jesus can't appear to anyone. But the existence of Jesus, combined with the well-known existence of Gnosticism perfectly and simply explains Docetism as a historical phenomenon.