Muslims, like those of many faiths, are compelled by their religion to praise the Creator, take care of each other, and take care of the planet. Those are their sacred mandates, as written in the Quran. While the call to love Allah and one another won't surprise many, the deep and long-standing convergences between Muslim theology and environmentalism aren't widely recognized within other religious and secular cultures at large or even among some American Muslim communities. In this unique project, Ibrahim Abdul-Matin seeks to change that. "Green Deen" ('deen' means 'way' in Arabic) is a call to devotion, prayer, and service, a 'friend-raising' project, a community-building opportunity, and a marriage of faith and reason. Abdul-Matin draws on research and interviews with prominent Muslim scholars, theologians, and community leaders to trace Islam's historical and contemporary preoccupation with humankind's collective role as stewards of the Earth. He reveals how Islam's call to reflection specifically includes reflection on our relationship to the natural world, and he cites scriptural passages that implicitly and explicitly illustrate our collective responsibility to maintain and manage the planet's delicate and intricate systems. If we all hope to save our planet and build stronger interfaith and secular relationships, Abdul-Matin argues, Muslims need to remember they have a history of a green deen, and the rest of us need to build community with eco-friendly Muslims. Advancing a mantra of 'water, waste, and watts', Abdul-Matin presents specific ways in which Muslim communities and religious centers could concretely benefit from adopting green strategies (such as getting mosques off the grid and ensuring local communities greater protections against hazards like urban brownouts).