In this article, we argue that the current crisis of civilization and the countless social and environmental problems we face today are the result of a culture of materialism that emerged out of the industrial revolution and has, over the past century and a half, become a kind of universal religion that claims absolute authority and shapes all aspects of human life – social, environmental, economic and cultural. In this article we demonstrate how prevalent but erroneous assumptions about human nature as predominantly individualistic, competitive and selfish contribute to a materialistic culture that is environmentally, economically, socially and culturally unsustainable. We examine, for example, the implications of materialism on technology-adoption, conceptions of beauty and international financial crises. We then argue that these prevalent assumptions are incompatible with what we demonstrate as true human nature informed by biological and social sciences, religious scripture, spirituality and indigenous beliefs. Finally, we suggest how science and religion, as two complementary systems of knowledge, can inform and achieve a sustainable future for humanity. We explore the spiritual roots of sustainability to paint a different picture of human nature, which is essential in building a society founded on the principle of the oneness of humankind and the convictions that underpin it. We also make the case that spirituality, defined here as a practical expression of a deep understanding of the nature of reality, should be more widely considered in the sustainability discourse as it is closely associated with the motivation to implement sustainable structures and practices. In writing this, we hope to set a foundation for further exploration of how spirituality can inform sustainability policy and practice and suggest that its role should be more closely considered.