There's quite a bit of versatility that can come with this topic. The Gospels offer us a lot about who Jesus is and why he was here.
What did he do while he was here? How did the disciples so easily drop everything to follow this unknown man? Why did he speak in parables? How is it all relevant to me today?
These are just a few subjects to be touched on if this is the topic you choose. I'll work with you and your event on what direction to take this one.
