The question confronts us, too: Who is this man? What authority does he have? Why should we trust him? The Christian faith centers on Jesus Christ. We need to understand what kind of person he is. See Jesus: Who is this man?, by Michael Morrison. 

Suppose one day an astronaut from some far-off galaxy entered my office. Suppose our space traveler was interested in the cultures and religions of the earth, and asked me: "What is this thing called Christianity? Could you tell me please what it is?" I don't know what all I would say in response, but I know what my opening line would be: "Let me tell you about a person whose name is Jesus." See Why the historical Jesus matters, by Stephen Davis.

Did the Gospel writers create their own fake Jesus stories and statements, or did they faithfully preserve his teaching? The question is of more than casual academic interest. If the Gospel writers created a theological hoax, their books would not be "gospel truth." How could they be the word of a God who does not lie? (Titus 1:2). See The search for the real words of Jesus, by Paul Kroll.