The book "Who Is This Man?: The Unpredictable Impact of the Inescapable Jesus" was written by John Ortberg. It discusses the impact Jesus has made on the world despite the fact that so little is known about him.
John Ortberg is a senior pastor at Menlo Park Presbyterian Church, an Evangelical church in Menlo Park, Calif., as well as a speaker and author. He holds a Ph.D. in clinical psychology and is the author of over a dozen books. As of 2014, "Who Is This Man?: The Unpredictable Impact of the Inescapable Jesus" is Ortberg's most successful book, as it debuted at number 3 on Amazon's new release chart in August 2012.