Consensus among historians and scholars?
The Wikipedia page (as of writing this) about "Historicity of Jesus" seems strangely unencyclopedic, and almost seems to have been written by a Christian apologist rather than unbiased editors. Indeed, it makes strong claims that use rather unencyclopedic language. Much of the article is worded like it were someone's opinion piece in an online forum or blog, rather than an encyclopedia article.
And, indeed, almost all of the citations refer to Christian scholars and historians, almost none of them to secular historians. The amount of bias in these sources is undeniable (as no Christian scholar would ever argue against the historicity and existence of Jesus, as that's the most fundamental core tenet of their belief system.)
It is, thus, very strange for the article to make strong claims such as "virtually all scholars who have investigated the history of the Christian movement find that the historicity of Jesus is effectively certain", when almost every single "scholar" being cited is a Christian theologian or apologist. It would be much more accurate and honest to write "virtually all Christian scholars", as those are almost exclusively the ones being cited.
It is indeed an extremely common, almost universal, argument among Christian apologists that the existence and historicity of Jesus is not only undeniable, but also very widely agreed upon among historians, and that pretty much no scholar of any repute, no matter what their personal belief system, doubts this.
Yet, both their evidence of this (ie. that the vast majority of historians, even secular ones, agree with them) and their arguments for the historicity of the man, are extremely weak and lacking. I have not found any survey, study or paper that would investigate what the percentages are on the opinions of professional scholars and historians, especially secular ones, about this subject. The only thing I have found (and what the Wikipedia article is able to cite) is claims by Christian apologists and theologians that this is the case. Claims with little supporting evidence. This is being asserted with strong conviction, but not much proof is being provided. Only a small handful of (alleged) non-Christian scholars are ever cited as evidence that this is a vast majority consensus among the academia. And the only people I have ever seen make these assertions are Christians themselves.
Non-Christian evidence for the historicity of Jesus?
What is the (unbiased) evidence provided for the historicity of Jesus? Why are these Christian scholars so sure that he was, in fact, an actual real person and that this is completely undeniable based on every source we have?
All the evidence provided seems extraordinarily weak, considering how strongly these apologists assert that his existence is "an undeniable historical fact".
The historians Josephus and Tacitus are two of the most commonly cited early non-Christian sources for the historicity of Jesus. These two names always appear when a Christian apologist is asked for historical evidence. Yet, curiously, you'll almost never hear them mention, without them being asked, when these two people were born. Almost invariably the apologists will leave it unstated and vague when these two historians lived, and when they wrote their texts mentioning Jesus. One has to wonder why.
It may well be that they leave that information out because if their listeners were aware of it, it might erode the credibility of their sources. Josephus was born in 37 AD, and Tacitus circa 56 AD. Well after Jesus's alleged death.
In other words, these two most famous non-Christian historians that are always brought forward when the question arises, were not even born during the (alleged) lifetime of Jesus. They were hardly contemporary witnesses to the events. The writings of Josephus that mention Jesus were written in around 96 AD, and the writings of Tacitus were written in around 115 AD. Both well over 50 years after Jesus's alleged death, neither historian having been even born at the time.
One would think that if, as the Christian apologists claim, there's an abundance of historic evidence for the existence of Jesus, they wouldn't need to resort to the writings of two historians who hadn't even been born at the time, and wrote their texts well over a half century after the alleged events. Certainly, if I were asked to give evidence for the existence of a famous person, like for example Albert Einstein, I wouldn't have to resort to citing the writings of some historian who was born 10 years after Einstein died. I would, rather obviously, cite texts written during Einstein's life.
Yet, such contemporary writings about Jesus seem suspiciously lacking. In fact, there exist no known nor surviving writings about Jesus that are contemporary to his alleged life and acts. Not even from Christian sources.
The fact is that both Josephus and Tacitus were simply writing about what Christians of their time believed and claimed. The only thing that their writing is evidence of, is that Christians, and their beliefs, existed by the year 96 AD (a claim that's hardly controversial). They are not evidence that the claims of the Christians of that time were real and accurate.
It is, thus, extremely strange for any self-respecting honest scholar or historian to give Josephus and Tacitus as evidence for the historicity of Jesus. They are evidence of Christianity having existed by that time, not that everything they claimed (eg. about Jesus) is factual. Josephus and Tacitus are very valid sources for the history of Christianity in the early second century, but they are extremely weak evidence for the existence of Jesus himself. Citing them as strong evidence for the latter is both fallacious and very dishonest.
Evidence from Christian sources?
Unsurprisingly, Christian apologists will use their own scriptures as evidence for the historicity of Jesus, regardless of the rather obvious bias of the authors. But even ignoring this blatant bias, do even these sources hold up to scrutiny?
Arguably, and without much controversy, the Pauline epistles are the earliest surviving writings to ever mention Jesus in any way, shape or form. However, even by the author's own admission, he never himself personally witnessed Jesus, never met him, never saw any of his acts. He only had second-hand accounts about the man. He was not, thus, an eyewitness to any of the alleged events, or even to the existence of the person himself.
Also it should be noted that Paul's writings are very lacking in any biographical detail about Jesus. Even if he was writing about a real person who actually existed, eg. some kind of Jewish preacher or cult leader, his writings do not reveal much about his life, only about his teachings. Even then, it's almost impossible to know how much of these teachings were the words of this Jesus person, and how much were the inventions of Paul himself.
The other letters of the New Testament, written by other people, probably much later than Paul's letters, are not much better in this regard either. They, too, reveal little to no biographical details about Jesus, and mostly deal with Christian doctrine (from which, once again, it's impossible to tell if they are the opinions of the writer himself, or the actual words of the supposed Jesus person they are attributing these thoughts to.)
It is almost universally accepted by serious scholars and historians, even most Christian ones, that the Gospels were written much later than the Pauline epistles, by unknown authors. Most secular scholars would agree that these writings are by far and large completely mythological and fictitious, containing little to no accurate information about Jesus, even assuming they are loosely based on a real existing person. Even the more mundane parts of the Gospels (ie. those that do not deal with any supernatural events) are likely to be fictitious. It is quite likely that the gospels, which are probably based on one or two original sources, are a largely fictitious "origin story" for the (alleged) founder of Christianity. Due to their mythological nature, the Gospels are extremely weak evidence of a historical Jesus, even one who did almost nothing of what is described in the texts.
Using the Gospels as evidence for a historical Jesus is like using the Historia Regum Britanniae as evidence for a historic King Arthur, or the Kalevala as evidence for a historic Väinämöinen.
One of the strangest (and weakest) arguments often given for the veracity of the scriptures is that of "criterion of embarrassment" (also mentioned in the Wikipedia article): The claims about Jesus are believable because his followers wouldn't have invented a story about him being humiliated and ignominiously tortured and killed by the Roman oppressors, with him being unable to do anything about it, rather than him being a great victorious leader and inspiration. If early Christians simply invented the story of Jesus, who was supposed to be the promised Messiah that would liberate them from the oppression of the Romans, surely they would have not made him such a weak person who ended up being embarrassed and killed by those same oppressors?
This argument holds no water. Martyrdom was a very common trait in many contemporary and much older stories and writings, including biblical ones. The Old Testament scriptures themselves are full of stories of pious men of God who suffer at the hands of evil people. Being martyred, rather than being a conqueror, was a very common trait in the stories about God's chosen people. In fact, the fate of Jesus in the Gospels quite closely follows what many Jewish scholars interpreted the Messiah to be like, from the Torah scriptures, which describe a suffering Messiah who is tortured and killed. It is quite probable that the authors of the Gospels were fitting Jesus into what they interpreted the Torah scriptures to predict about the Messiah, which was probably a common story among Christians of the time. (This is precisely where you get all the "the Old Testament predicted Jesus" claims among Christian apologists. Of course it "predicted" him, because the authors of the Gospels made him fit those "predictions".)
Martyrdom, dying for the cause, is and was a very common heroic narrative. Many stories, even very old ones, have their heroes die ignominious deaths and meet shameful fates even after heroic acts. This is not something unusual. (In fact, it might even be more common in stories from antiquity than it is today.)
The man versus the myth
Many historians like to differentiate between real historic people, who actually existed, and the myths that were created around them. Myths may be formed around a real person, but the myth itself may have little to no resemblance to the actual person, or the actual events. Much of these stories may be complete fabrications or distortions.
Thus, many historians like to separate the actual person from the fictitious character invented loosely based on that person. As an example, Blackbeard, the famous 18th century pirate, was a real existing person, real name Edward Teach. However, much mythology surrounds the man, and it's dubious how many of the events and actions attributed to him are real, and how many are exaggerated or even completely fictitious. Thus, some historians like to differentiate between "Edward Teach the man" and "Blackbeard the fictitious pirate", even though the latter is largely based on the former.
Even if there existed some kind of Jewish preacher or cult leader, perhaps even named "Jeshua" (or who called himself as such), and even if the Christian religion, mostly built and spread by Paul, was based on some of the things that this person taught, a difference can be made between the real person and the mythological Jesus described in the Gospels and alluded to by the New Testament letters.
I think making this distinction is important, for intellectual honesty. When someone makes the claim "Jesus was a real historic figure who actually existed", it's deceiving and dishonest to equate this possibly existing real person with the mythological Jesus that Christianity believes in, described in the Gospels. For all intents and purposes, even if a real person existed, it was a completely different person than the "Jesus" that Christians believe in. Many historians like to separate "the man" from "the myth", and I think that should be done here as well.
Did a real person exist, perhaps even some kind of preacher and cult leader, on which the story of Jesus is based on? Maybe, maybe not. However, did the "Jesus" described in the New Testament exist? Probably not, in this sense.
Claiming that there's strong evidence for the historicity of Jesus, and that the vast majority of scholars and historians agree, is deceitful and dishonest.
