This segment originally aired live on July 16, 2013. That original audio is posted here, although an edited version was included as part of a best-of Brian Lehrer Show episode on December 27. 

It's Five Pillars of Islam week on The Brian Lehrer Show. Every day this week, we're hosting an interfaith conversation based around the Five Pillars: Shahadah (faith), Salat (prayer), Sawm (Ramadan), Zakat (charity) and Hajj (pilgrimage). Today: we'll talk to our guest and take calls on Shahadah (faith) in relation to Islam and all the major monotheistic religions. Reza Aslan, associate professor of creative writing at the University of California, Riverside and author of Zealot: The Life and Times of Jesus of Nazareth (Random House, 2013), talks about his book on the "historical" Jesus.