"When Jesus finished these words, the crowds were astonished at his teaching, for he taught them as one having authority, and not as their scribes." (Matt 7.28-29)I find that really interesting: "he taught them as one having authority, and not as their scribes." It's more curious when you consider that the scribes actually were recognised authorities, whereas Jesus was a simple "layman."
"Having authority," in this case, clearly does not mean having "official" authority, as in an ordained position. So what is this "authority"?
Br. David Steindl-Rast, a Benedictine monk, gave a terrific answer to this question in an interview that was published in What Is Enlightenment? magazine a while back. He said:
Jesus placed the authority of God, which was always seen as external, in the very hearts of his hearers. The core teaching of Jesus is not, "I am going to tell you all," or anything like that. No, he presupposes you know it all. "Don't you know it? I'll remind you of it. You know it all." This is his typical voice. This question opens many of the parables, "Who of you doesn't know this already?" It's not sufficiently emphasized nowadays in Christian teaching, but the moment you are alerted to it you see it.In other words, Jesus was seen as having authority because the truth of what he was saying did not depend on some external source of validation. He didn't require blind faith, and he didn't ask anyone to just take his word for it. He persuaded people to the truth of his teachings by appealing to what they already knew.
I think this accords well with the notion, found in some forms of Mahayana Buddhism (like Zen, for instance), that we are already enlightened, but most of us don't know it yet.
By the way, you can read Br. David's interview here.