Honestly I don't think this book has anything to do with religion, right or wrong. Any type of theorizing, philosophy, formal religion, or even societal emphasis on what is important is represented as something negative. For example, all church figures are corrupt, philosophers Pangloss and Martin no matter what their opinions are either ignorant or miserable. The happiest (and eventually model) character is the farmer, who thinks and works for himself. Voltaire was jaded by the corruption of religion and hopeless optimism of philosophy and as a result was a proponent of the theme he ends the book on to "tend one's own garden".