The fact is, that we interpret accordingly.
And the bible is and always was open to interpretation.
We cannot even prove if the sermon on the mount was delivered by anything other than a man, or if at all.
Though charismatic people and their ideology, have always been able to delude the gullible.
Yes and no.
People do interpret the bible differently. Some start with the newspapers. Some start with their own experiences. Some start with their prejudices.
Some however - academics and scholars - start with it the way they would start with any other book and try to understand firstly what the author is saying - by considering the time and culture it was written in - by considering the audience they were writing to - by considering the differences in cultures between both of these things - and then draw a conclusion. This is why academics and scholars - tend to draw similar conclusions - and continually do so - because the study of language and interpretation is a scientific methodology. But you say - why the different interpretations then? Aha - because like anyone who has ever studied science will tell you, when new information arises, it changes the variables. And when the variables change, so does the interpretation.
Of course the new information has to be analysed - studied and tested and then it can be factored in.
This is why people from all types of backgrounds, whether Christian, Jewish, Muslim, agnostic, atheist can have a certain amount of shared conclusions regarding the OT and even the NT.
But others don't share that accepted framework for interpretation - they simply interpret it according to their own subjective methods. this happens a lot in christian circles. it happens a lot in atheistic circles. It happens far too often. So yes, you are correct, people interpret the bible subjectively in many many cases. Yet, there is also an extensive amount of objective work done, using the scientific method.
You can choose to go by the conspiracies of some - and you can choose to reject the science of interpretation as well. That is a matter entirely for you. Yet this does not mean that others have to agree with your interpretation that the bible is up for grabs interpretation wise. There is a proper way of reading books and then there are non-proper ways. One improper way is to speculate that there is a secret message underlying the narrative of a book.
Stephen uses a book - the secret gospel of Mark - as the basis for his speculative interpretation. It is a book which has been demonstrated conclusively to be a fraud and fake. Stephen does have some trouble discerning fake from true - he even considers the former President Trump to be the best prime minister England never had.
Now not withstanding your views about Trump, even an American - (And Americans are generally known as awful in respect of history and geography) would realize that Trump is not an Englishman. I know he looks a lot like their current PM - the hair and all. But really and seriously.
I also find it very interesting that you believe the lies that "we cannot prove" stuff about the bible. We cannot prove anything more than 5 minutes ago. It is credible historians and academics who have are confident - that Jesus lived. There are some questions about what he did and whether he wrote anything at all. Yet, the general consensus is that Jesus lived in the time frame the gospels indicate. Are their dissenters? Of course. Just like there are dissenters in relation to the earth being a sphere. You can be a dissenter - go and join the flat earth society.
The Flat Earth Society (tfes.org)
I am sure they would welcome your theory that - all interpretations of everything are up for grabs. And that there is no scientific methodology widely understood to read and to interpret books and language.