The engagement of religious diplomacy within the United Nations systems has become increasingly important for achieving the Sustainable Development Goals. The editors argue that effective religious diplomacy must reflect the great diversity of religious and spiritual expressions within human communities. The editors argue that this can best be achieved through a worldview shift within the United Nations systems. Religious engagement in the United Nations systems has been understandably constrained by limited and formal organizational structures and conventions. However, the existing patterns of engagement mitigate against the very goals they seek to achieve. The editors argue that expanded, yet measured, religious inclusion will strengthen social cohesion in the global community. Contributors demonstrate how communities become stronger when marginalized minority voices are included in public discourse. The editors further argue that governance has a responsibility to ensure a safe environment for this interaction. The editors propose that the United Nations adopt the posture of "loyal opposition", that is inherent in parliamentary democracies, to serve as a guideline for expanded religious engagement. The contributors advance this proposal with illustrations from multiple contexts that address a diverse array of social problems from perspectives rooted in theory and practice.