So, tonight, (thankfully former) President W is speaking before the "let's all convert the Jews to Jesus" conference in Texas. Rachel Maddow has been covering this since the story broke last week.
Without belaboring the 'peculiarities' of this group's beliefs, I, too, am trying to figure out his motivation, and it comes down to the following possibilities:
1) He doesn't really believe in the group's stated goals, but the money is too good to pass up.
2) He does believe in the group's stated goals, and the money is just a nice bonus.
3) He does believe in the group's stated goals, and the money is totally irrelevant.
And now, my choice for most-believable explanation:
4) It doesn't matter whether he believes in converting Jews or not. He made up his mind to do this gig, and The Decider does not ever change his mind.
By the way, I hereby award Rachel Maddow's writers the 'Best Use of Yiddish Today' prize, for accompanying this story with a slide with the words 'Meshugganah Accomplished'.