As a writer, I have the wonderful privilege of researching and meditating on one topic for months at a time. My latest project allowed me to focus on the grandest subject of all: Jesus. Growing up in the church, I learned his name as soon as I learned the names of my family members. But now, as an adult, what did I truly think about him? Which childhood impressions had been confirmed and which ones overturned?

As I reflect on what I learned in the process of writing "The Jesus I Never Knew," I have come up with a "top ten" list. Please forgive me if the form seems irreverent. David Letterman style, it begins with number 10 and works upward.

I knew that, of course. But the more I studied Jesus, the more I realized that his humanity had receded far away. Every week in church I would repeat the creed, which, significantly, hustles through Jesus' life. "… Born of the Virgin Mary, suffered under Pontius Pilate," it says. Did anything happen in the interval between birth and death?

Somehow, everything Jesus said and did in 33 years on earth gets swept aside in the rush to interpret his life correctly. For me, as for many others raised in the Christian tradition, the man who walked the dusty roads of Palestine had been all but lost. I knew Christ—"Light of Light, very God of very God, begotten, not made"—but not Jesus, or Rabbi Jeshua bar-Joseph, the Jew from Nazareth.

A remarkable change has taken place in recent years, I learned during my library research: interest in Jesus is resurging among the Jews. In 1925, the Hebrew scholar Joseph Klausner could find only three full-length treatments of Jesus' life by contemporary Jewish scholars. Now there are hundreds, including some of the most illuminating studies ...