R
Are we not to believe our Most High God not only knew exactly what would be written, what books we would be cannonised etc? So really at the end of the day it is all the inspired Word of God which we have no right to tamper with, however for when you are first learning and you get something wrong or misinterpet it His grace is sufficient. It is why he tells us to always be teachable and able to be corrected so we wouldnt carry on making these mistakes, so wise counsel is needed and the Holy Spirit is able to teach those listening. You are only accountable for what you know. The rest of the bible didnt need a warning because when He said it was God breathed that would be enough of a warning to say its Me through the My Spirit inspiring these human writers. I think the warning was needed to actually be said in Revelations because of the kind of book it was(i.e pictoral and symbolic). Which causes people to want to explain it away leaning on their own understanding.