My understanding is that the book of Enoch was held in high regard until sometime after the new testament was canonized. (Second century Apostolic fathers such as Justin Martyr and Irenaeus, Polycarp’s successor, hailed it as Scripture.) Jude and 2 Peter quoted directly from it. The new Messiah seems to have gotten a big part of his providential understanding from it and Genesis 6; ie., the idea of sex between angels and humans is what contaminated God's original ideal. Mix this with Q divulging the fact that "we are not alone in the universe" and you have a whole new "can of worms" to deal with.  Obviously, somebody wanted to keep this "angelic" reality hidden as it can give power to those who understand the origins of evil and decide to tap into it like the Luciferians have done. Hitler tapped into it. Apparently the inner circles of the Freemasons and Rosicrucian tapped into it. So did the Sabbateans and Frankists. (Which is where the Rothschilds/Illuminati got its origins.) So, yes, scriptures have been altered in the sense of what has been omitted or deliberately ignored. For instance, Abraham (Abram) had a father who was a Sumerian oracle priest. Which all connects us to the Anunnaki "gods" and the original Garden of Eden story. Heretical? Yes. Historical fact? Yes.