In a world facing severe ecological crises, secular strategies alone often struggle to inspire long-term behavioral changes. This paper explores how religious education can act as a crucial catalyst for sustainability ethics by shifting environmental care from a legal chore to a deep spiritual duty. Religious lessons offer a unique space for sustainable development, allowing students to build ethical literacy and practical values. Utilizing a reflective inquiry methodology, this study examines how theocentric worldviews across different faiths, such as Islamic stewardship and Catholic social teachings, provide strong intrinsic motivations for conservation. While innovative pedagogies like digital gamification and experiential service-learning show great promise in engaging students, several systemic barriers still remain. Significant gaps in teacher training are often made worse by rigid curricula and fragmented educational policies that separate subjects into isolated silos. Ultimately, balancing sacred traditions with modern interdisciplinary collaboration is essential for transforming classrooms. By offering a practical framework for curriculum reform, this article highlights why integrating faith-based ethics is vital for cultivating active, compassionate stewards of our shared planet.