If a pharisee had happened along, and the eunuch inquired of him the meaning of the scripture, he would have gotten a very different answer, although this man would have claimed to be an authority. You have no way of knowing if what a man teaches is true, unless you yourself have no discernment.
that should be "some" discernment
Yes, I do, -- it is called apostolic authority. You don't recognize it, so you don't know who to listen to. Speak for yourself please.