In his bestselling new book, Zealot: The Life and Times of Jesus of Nazareth , author Reza Aslan’s goal was to write a biography of one of history’s most influential people, drawing on historical sources instead of the traditional Gospels to help people understand the man who would one day be called the Messiah. Wharton legal studies and business ethics professor G. Richard Shell recently talked with Aslan about the life of Jesus, what Jesus taught us about leadership, and how a leader’s message can sometimes change after his or her death.   An edited transcript of the conversation follows. G. Richard Shell:  My name is Richard Shell. I’m here with Reza Aslan, the author of Zealot: The Life and Times of Jesus of Nazareth and someone who knows more than probably anyone else today about the facts regarding the life of Jesus. Welcome, Reza. Reza Aslan:   Thank you for having me. Shell:   I’m curious about how this book came to be next on your plate.…