The most disturbing aspect of the religious world and their thirst for supernatural experience and supernatural encounter is their claim that God is still revealing Himself verbally to them. They claim that God is speaking to them; that is a constant claim.
It has been a curiosity to me and should be to us, I think, that if God is still giving revelation, the only ones that He gives it to are founders of various cults.
The Rambam said just like one can not and must not add to the written law so he must not add to thee oral law.
In the more spiritual sense the oral and written law [Old Testament and the two Talmuds] are the standard by which you measure truth.
Just to give you a little deeper insight into that, the Old Testament Canon was closed about 425 B.C.. The last prophecy was written by Malachi, placed into the canon.
Now there were many attempts made by Satan to infiltrate the Old Testament with uninspired books. At least 14 of them have been accumulated and together they are called the Apocrypha. They are not a part of our Torah. They are not inspired books. They are books 1 and 2 Esdras, Tobit, Judith, the rest of Esther, the Wisdom of Solomon, Baruch, the History of Susanna, the Prayer of Manassas, and 1 and 2 Maccabees. All spurious. They were clearly fakes. How do we know they were fakes? They were written long after the canon was completed and they lacked the prophetic quality and authorship to stamp them as inspired Scripture. None of their writers claimed divine inspiration and some openly disclaimed it. And Apocrypha books contained errors of facts, errors of ethics, errors of doctrine.
For example, some of the Apocrypha books advocate suicide. Some of them advocate assassination and some of them teach praying for dead people. The Old Testament was unquestioned; it is still unquestioned because it is so evident what was inspired.
There is now also a formidable group of fakes
These are were attempts to pollute the authentic Law of Moses text with spurious revelation. Now, listen to me. That attempt didn't end in those days; it is still going on. People and groups have continued to claim their works and their writings are inspired by God, and are true, and authoritative and binding. And whenever they do that, it leads to aberrant doctrine.
To add anything to Torah or to downplay the singular, unique, inspiration of Torah, then is to not only go against the Word of God ("Thou shalt not add nor subtract from this law I give unto you this day."), but it is to bring yourself into the very dangerous place where you are susceptible to the curse of God. And, of course, what happens when you introduce something as true is you open up a spiritual free-for-all, unintentionally perhaps.
The religious world today has initiated that free-for-all as serious as any error in that movement is the error of claiming revelation from God. It is reckless; it is indiscriminate.