What are the motifs in Lamb: The Gospel According to Biff by Christopher Moore?

Humor and life are recurringideas in the book. Biff possesses an unshakable sense of humor. This helps him through the tough times that he and Joshua must face in childhood and adulthood. Joshua often appreciates the humor and shows this with his attempt to understand how it works. The problem is that humor needs to be felt and known intuitively in order to perform it. Analysis can be done and the process explained, but that does not substitute for intuition and never makes a good comedian.