This article reviews religious engagement in foreign policy as well as international development based especially, albeit not only, on the legacy of work carried out for over five decades by the world’s faith leaders, together, in and through Religions for Peace. The article also provides some lessons learned from the author’s own experience in intergovernmental, academic and international nongovernmental organisations of engaging with religious actors. While noting the unique heritage and capacities of religious organisations and leaders, including in challenging contexts, the author also shares concerns about the ongoing relative scarcity of multireligious collaboration and investments, which are deemed to be the tipping points for building socially cohesive and environmentally sustainable polities.