What is the theme in The Gospel of the Flying Spaghetti Monster by Bobby Henderson?

The central theme (and debate) of this Gospel is the validity of Intelligent Design as a science, ergo fact versus faith. The author is biased in his belief that Intelligent Design is not scientifically based and has no place in a science curriculum, so he writes with a persuasive point of view. His book uses a god of his own creation, the Flying Spaghetti Monster, to satirically demonstrate how any faith could have as much scientific credence as Christianity. By painting an absurd picture, yet using similar arguments such as presumptive theories based on questionable facts, Henderson gives a strong, one-sided argument for his case.