Jer 31:33 But this shall be the covenant that I will make with the house of Israel; After those days, saith the LORD, I will put my law in their inward parts, and write it in their hearts; and will be their God, and they shall be my people.
Jer 31:34 And they shall teach no more every man his neighbour, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more.
the scripture above is speaking to Isreal, I understand that to be spiritual Isreal the true Isreal the children of promise. not a fleshy jew born to isreal, although those can be included cause it is open to all.
they will no longer teach eachother of God because they will know him, he says from the least of "them" to greatest of "them" the "them" is Isreal those given the Spirit of adoption the ones who are grafted in.
now the ones with Holy Spirit need no teacher because its the Spirit that teaches them, that is not to say they cannot learn from eachother. And is not to say they all know the same or all get to same level or all know the same at the same time. but the Spirit in one will agree with the knowledge from the Spirit in another if the knowledge overlaps because it is from same truth. The spirit teaches One truth, even if one may get more of it than another.
Joh_14:26 But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
the above scripture is Christ himself telling them who will teach them. When you read the story of Christ notice how He told em a whole bunch of stuff while He was with them but they never really got it till they recieved the Holy Spirit.
so Christ taught them but they couldnt really get it till the Holy Spirit was given to them and then the Holy Spirit brought them to rememberance of what Christ said and show them the Truth of the matter. The Spirit teaches Spirit.
teaching is a gift given by the Spirit, its the Spirit teaching through them. That in no way conflicts with them not needing a man to teach them.
now as far as false teachers, remember how He said things would get even worse ? look at all the false teachers Christ came across, now know the amount of false teachers is far far worse than then.
God can teach you anything He wants in any instant He wants or block anything He may not want you to know. He is all powerful and can destroy planets and lives at his whim. so why would anyone appeal to man for knowledge when the most powerful one and the one with all the answers is God ?
He is the only one who can lead us into all truth.