Who is Bartholomew from Lamb: The Gospel According to Biff and what is their importance?

Bartholomew is the town idiot in Nazareth. Biff discovers that the idiot is actually a very intelligent Greek philosopher who follows the ways of the ancient Cynics. This philosophy rejects society, personal hygiene and promotes crazy behavior in the pursuit of happiness. Bartholomew becomes Joshua's first disciple and one of the apostles.