The Certainty of Doubt...

I’m watching Bill Maher’s ‘Religulous’, and he says that he’s in the business of doubt. He said that christians sell certainty, while he sells doubt, but he says it and sells it with the same certainty that a christian sells certainty; I mean he speaks and religulously sells his absolute faith in doubt, conviction of doubt, and certainty of doubt, like a man of religulous certainty...doesn’t that make him a man of faith in doudt, or am I just being religulously, religulous?