Your quote was prior to John.
Are there people out there getting bit by poisonous snakes and shaking them off into a fire?
Are there people out there writing new books to the Bible?
The answer to both is no.
The apostles and wrote the New Testament which closed with John.
Jesus said everything went continue until it was fulfilled. The role of the apostles has been fulfilled.
Yeah, ok. You say one thing, the bible says another. God must have made a mistake.