Well, historians are not scientists, either. Are there any actual historians who study the historicity of Jesus? I ask because as I noted you seem to simply dismiss the experts on the matter by the use of an ad hominem. So far you've not actually made the demonstration that I'm asking for.
We are not talking about "historians". The people you are claiming as "experts" are Christians who are employed as Biblical Studies teachers.
Are there any actual neutral independent historians who normally write about research into the "historicity of Jesus"? Answer is - I do not know if they are any or not. But if there are any, and if they follow Bible Scholars in presenting the bible as evidence for a Jesus who they claim is certain upon such evidence, then they too would be making a claim that is entirely unwarranted and without credible foundation.
What other "demonstration are you asking for?
Ian, you really should realise that your claim that this bias is inevitable and overwhelming is the thing I'm questioning. I do not accept that your claim, on its face, is sound. Can you demonstrate that it is, or not?
What do you mean by a "demonstration". You have asked me to explain why Bible Scholars would "inevitably be biased" in concluding that Jesus was "definitely" real, and I have explained exactly that to you in detail several times now ...
... do you want that same explanation again?
The explanation is that almost all those Bible Studies scholars who you are relying upon as "experts" whose opinions we should trust and whose conclusions we are not qualified to dispute (according to you), are lifelong practising Christians ... which means that even before they knew any detailed evidence at all from degrees in biblical studies, they were already totally comitted to a belief in Jesus, God, and the truth of the bible as their source of belief ...
... as a practising worshipping Christian, you cannot do anything else other than to insist that Jesus must have existed (if only as a mere mortal human), otherwise if as a Christian Bible Scholar you do ever finally admit that having studied all that has been offered as evidence for Jesus, you must now in all honesty conclude that he did not ever exist (or that it's quite possible that he never existed), without making a complete mockery of your position of still claiming to be a Christian believer! The two positions are completely incompatible with one another.
What other “demonstration” are you realistically demanding? Look – the situation is that we have tens of thousands of devout Christians who pursed their religious interests far enough to forge a career lecturing Biblical Studies. If you ask any of them for evidence that Jesus was a real person, every last one of them will present to you first as their primary most convincing evidence, the gospels and letters of the bible …
… but unless they are entirely blinded by their own religious faith, then they really must know that the bible is not a credible source of reliable evidence for a real “historical Jesus”. So why do they all insist on repeatedly using the bible as their evidence? Is the answer because they are all liars and frauds? I don't think so. I think they do all really believe that the bible is a fine source of the evidence. Or is it because the bible truly is a reliable source of credible factual evidence for the life of Jesus? Well … if you think the bible is such a factual reliable source then we can stop right there, because only the most deluded of the faithful could believe that. Or is it because without clearly realising it themselves, those Christian Bible Scholars have deluded themselves by such things as “Confirmation Bias” into believing that at least some scraps of vital truth about Jesus can be teased out from a huge mass of what is now known to be quite obvious, and quite unarguably, a huge pile of untrue religious miraculous myth-making?
I think it's the latter. i.e., Christian bible studies teachers are showing unintentional but nevertheless quite massive levels of delusional bias when they believe that a source such as the bible can be credibly presented as evidence sufficient to claim “Jesus definitely existed” (and that's a direct quote from Bart Ehrman, who has kept on repeating those words long after it has been pointed out to him that he really cannot truthfully make such a claim upon any known evidence).