Last Updated September 5, 2023.
Bruce Barton's novel, The Man Nobody Knew, is not necessarily a piece of fiction. (The counterargument will be discussed later.) Fiction texts are the ones which typically possess characters. By definition, a character is a "person" who appears in literature, and the author has created this persona. This persona is central to the author's storyline (plot) and message (theme/s). In other texts, called non-fiction, the people identified in the text are real. The text tends to illustrate what happened in the life of the person or people spoken about. These people tend to be called the subjects of the text.
Admittedly, only one subject's existence is highlighted in Barton's text: Jesus. He identifies Jesus as the original businessman. He illustrates the success of Jesus to justify the use of Him as the perfect leader. By doing this, Barton takes His (Jesus's) success in the past and describes how his past successes will translate into present success for those who mirror his actions.
Barton does include references to the Apostles in the novel. There are also references to leaders from the time of Jesus who were opposed to him, soldiers under the control of these leaders, and characters from the Bible (such as Sampson).
Any other references of people mentioned in the text are done so with respect to philosophical or historical references and/or research.
Some could argue that Jesus could be identified as a "character." Given not all of mankind recognizes him as a person who really lived, some may argue that Jesus and the stories about him were all created to teach the importance of morality, sacrifice, and redemption. In this case, any of the people mentioned in the text (from the Apostles to Sampson to Jesus himself) could be identified as fictitious. By denoting the Bible and the characters within it as fiction, all of the Biblical references to persons in Barton's book could be identified as characters.