Why Did Jesus, Moses, the Buddha, and Mohammed go to the Shack?

What is Paul Young (author of The Shack) reading? Find out here: http://www.startribune.com/entertainment/books/180612591.html?refer=y

Q What are you reading right now?
A Baxter Kruger’s book “The Shack Re-visited,” for obvious reasons. Jean Vanier, “Drawn Into the Mystery of Jesus Through the Gospel of John.” Also, the new book by Brian D. McLaren, “Why Did Jesus, Moses, the Buddha, and Mohammed Cross the Road?”