No major religion has a founder who claimed to be God, though some small short-lived cults have had them. While there have been self-deceived people in history who have made divine claims, they never were able to make their assertions believable except to a tiny group. Why not? It is impossible to convince people you are God if you have any of the normal flaws of human character—selfishness, impatience, uncontrolled anger, pride, dishonesty, and cruelty. And there are invariably people who live closely enough to the divine claimant to see all those flaws and who are thus able to see through the illusion. And if you add to this the deep cultural and theological skepticism of Judaism, you see that it would be impossible to convince a critical mass of Jews that you were God—unless that were really the most sensible explanation of the facts.
Historical scholarship shows us that, after his death, a fast-growing body of people, insisting they were faithful to Jewish monotheism, nonetheless began to worship Jesus as the one True God. What kind of life must Jesus have led to accomplish what no other person in history has ever done—convince more than a tiny percentage of unbalanced people that he is the Creator and Judge of the universe? What kind of person must Jesus have been to overcome the profound resistance of Jews to such preposterous claims? The answer is, he would have to have been like the incomparably beautiful human being depicted throughout the New Testament.
—Tim Keller, Encounters with Jesus, pp. 48-49