Were the Gospels just a brilliant rip-off of other religious leaders and cults? How much historical evidence is really out there for the existence of Jesus? What does this evidence show? What do scholars say?
You can listen to it at Premier Christian Radio.
You may also want to take a look at the latest books by both Marshall and Carrier:
Jesus Is No Myth: The Fingerprints of God on the Gospels
by David Marshall.
On the Historicity of Jesus: Why We Might Have Reason for Doubt
by Richard Carrier
Or search for them at your local library.