This chapter argues that we should abandon the idea that “sustainability” is about finding a way to preserve our present “system” – our prevailing economic worldview, our consumer lifestyle, and the accompanying practices and institutions. Rather, we should rethink the concept of sustainability as a tool for criticizing and rejecting as unsustainable the growth-based economic status quo and as a spur to the development of more ecologically oriented alternatives. One of the main barriers to recognizing the unsustainability of our present global political economy is the widespread influence of mainstream economic theory. A growing number of scholars have argued that the worldview presented by mainstream economics amounts to a new secular religion of sorts, a system of faith that has become dominant in today’s world. Helping students and the general public to learn more about this view of life and its far-reaching influence, and helping them to recognize and envision possible alternatives, is a main contribution that education about religions and beliefs can make to contemporary discussions of environmental, economic, and social sustainability.