Glenn Beck was a run-of-the-mill shock jock. Then, he moved to CNN, where he mixed humor with fairly light commentary. Then, he moved to Fox News, where he began ranting about Obama bringing about the apocalypse for hours a day. Why the change in demeanor? There's money in it. Lots and lots of money.
Jones may believe in the overarching themes, it's hard to say. The theatricality, the EVERY DAY IS ANOTHER DAY CLOSER TO THE UNITED NATIONS EATING YOUR CHILDREN nonsense that forms the backbone of what he says? Snake oil. There's no better way to convince your listeners of what you're saying than to stroke their ego, and Jones does the 'only you believers know the real truth' act better than anyone since the revival preachers of the South.
Yeah, he does go on about the end of the world scenario way too much. But all the stuff he says is backed up with statistics and facts.