Between AD 30 and AD 175, many Christian and non-Christian sources/writers testify to Jesus's existence.
See this page to analyze these 20 proposed examples:
This is relevant because Jesus died in AD 30 (or AD 33) and these reports represent a true diversity of independent attestations supporting his existence. These sources reporting on Jesus by and large were in a position to know the truth of the matter, and so have a justified belief. At the same time, there are no existing reports suggesting that people believed in a Jesus myth--not even one.
Among the four gospels are many stories of Jesus's sayings and deeds, culminating in his death by Roman crucifixion. As it happens, we can know that the Gospel stories are largely or entirely rooted in witness testimony.
This page analyzes 7 arguments:
The Gospels being rooted in witness testimony counts in favor of Jesus's historicity because these stories are precisely about a historical Jesus and his dealings. That these reports would exist is not at all surprising if Jesus did exist, but they are quite difficult or frankly impossible to explain if there were no historical Jesus.
The stories we find in the Gospels are often very “dissimilar” to church in AD 31-90. Their behavior and language which was quite discontinuous with post-Jesus attitudes. (This include post-Easter beliefs, expectations, styles, background, understanding, and preferred vocabulary).
See this page to explore 3 arguments:
Of course, this is significant insofar as these stories essentially presuppose an historical Jesus, and insofar as Christians are supposed to be the group of persons who invented him. The idea is that if this Jesus in the Gospels is radically different than they are (and in curiously consistent ways across sources!), then the hypothesis that they invented him becomes unmanageable.
In addition to reports explicitly on his existence, there are several justifiable facts about the historical Jesus which entail that he is a real historical figure.1
Consider one example (among many):
This is relevant because if we know things about a historical Jesus, then there must be a historical Jesus.
Miracles-workers are not going to be real historical figures. After all, miracles do not happen in the real world (e.g. because we know there is no God or because God obviously does not do that kind of thign). This fact comes in to play because, if Jesus existed, he was unquestionably a miracle worker. That is unacceptable, so it is better to say he did not exist at all.
But, by way of response
And so what if miracle workers can't be real historical figures?
There are various historians or general writers in the 1st century (or soonafter) which speak on this or that issues relevant to their time. And yet as we survey this particular list of writers, they make no mention of Jesus. That is to say, even if some historians to speak of Jesus, there are many writers of the time who do not.
In response, however:
Details about Jesus match the details of prior mythic deities or mythical figures.
A full page will analyze several alleged examples, e.g.:
This is relevant because to the degree that Jesus resembles pre-existing mythical deities, to that degree we have reason to suspect Jesus is a copy of these deities (and therefore himself mythical).