If it's an obvious fraud then you must believe they are liars and hucksters. And don't really believe what they say they believe.
Otherwise you end up with the argument that these very learned and credentialed men are stupid fools.
To the extent that they are making duplicitous efforts to pass off their religious beliefs as science, they are.
They're sole accomplishment to date is the sale of books, essays, and pamphlets to gullible marks on the receiving end of their con-game. And out in the twilight zones of social conservatism, their supporters both excuse their behavior and enable it by invoking a multicultural moral equivalency that is indistinguishable from distilled liberal drivel. "Teach the controversy (that we have invented from whole cloth)!" "Break down the rigid doors of science and let in the fresh air of fantasy!"
I have no doubts as to the sincerity of Philip Johnson, an obviously intelligent man.
One doesn't have to be stupid to be deluded. Emotions can prompt some of the smartest people to believe the most absurd things, against all reason and evidence. How else can you explain that a man smart enough to earn a Ph.D. in biology from a top university was deluded into becoming a Moonie?
I know some extraordinarily intelligent Mormons (and I even support one for president) who accept a religion that is almost laughable in its absurdity, though it's not quite as absurd as the cult of "Reverend" Moon.
I suspect the vast majority of the ID and creation "science" crowd, all demonstrably intelligent people, are similarly deluded.