Did Luther consider Erasmus an unbeliever, and if so, why?

The introduction to [*Luther and Erasmus: Free Will and Salvation*](https://books.google.com/books?id=IU_8JDjxL34C) mentions that [Luther](https://en.wikipedia.org/wiki/Martin_Luther) called [Erasmus](https://en.wikipedia.org/wiki/Desiderius_Erasmus) an unbeliever: > [Luther's] letters and the gossip of his Table Talk are littered with scorn of Erasmus as a trifler with truth, a scoffer at religion, an unbeliever. ([page 2](https://books.google.com/books?id=IU_8JDjxL34C&pg=PA2)) Perhaps this shouldn't be surprising, given Luther's penchant for speaking his mind, and Erasmus's humanism. Nonetheless, Erasmus was a committed Roman Catholic and a major biblical scholar. Thus, I'm wondering: did Luther actually explicitly call Erasmus an unbeliever? Where in his writings? And if so, did he do so merely on the basis that he was a Roman Catholic (i.e., he considered any Roman Catholic to be unsaved) or on some other basis?