In his book The Nine Questions People Ask About Judaism, Dennis says that Judaism does not believe in eternal hellfire. The one problem with this is that it is not true. There are plenty of places in the Talmud that describe eternal hellfire.
Dennis often sets up these rhetorical positions about the superiority of Judaism or whatever he’s advocating, and he’s just so convincing that you don’t think to fact-check him.
One reason that Dennis does not get much respect in many learned Jewish circles (with the David Hartmans of the world)is that he’s not that conversant with Jewish text. Like his friend Joseph Telushkin, he’s more of a secondary sources guy. He’s more of a popularizer than a scholar.