Language forms the central core of religious systems.
For example, Shakespeare was such an enormous force in welding a unity in the English language that it served as a paragon of exemplary imitation in speech and writing thereafter. The King James Bible smells like Shakespeare as a result. The problem with languages in flux is that there is nothing to keep the language from deteriorating in constant revamping and neologisms that are mostly regional colloquialisms. Shakespeare put the brakes on, so to speak, and slowed down the flux in English long enough for there to be an attempt at standardizing it.
The Pilgrims brought King James with them and the American language is chock full of that contrived purple prose at its inception.
That was America and England. Other countries had their sterling example of the written word used as "that which must be imitated".
In France, it was Victor Hugo's Les Miserables that froze the morphing of that tongue.
In the Middle East it was THE KORAN which ritualized the Arab tongue and made it unified.
And so on.........
I'd posit that it wasn't until the SEPTUIGENT (Greek!) that "scripture" for Jews became a common parlance of a literary exemplar which triggered the intricate plottings of redactors and popularizers of Judaism. This allowed the Synoptic nonsense to come into being.
All in all---to "prove" an orthodoxy you must have the written word.
He who controls the writing controls the mind of the believer.
(i.e. New World Translation)