As the World Council of Churches (WCC) celebrates its 75th anniversary, the world faces many challenges, including ecological crises, violence, pandemics, systemic poverty, racism, gender-based violence, human rights violations, and the war in Ukraine that began in 2022. Taking as its basis the Unity Statement agreed at the WCC's 11th Assembly in Karlsruhe, Germany, in 2022, which met around the theme “Christ's love moves the world to reconciliation and unity,” the article argues for an “ecumenism of the heart,” of which the statement spoke, as a path to unity. It underlines that this is a “public theology” based not on political abstinence but on a passion for and renewed commitment to the world. The article concludes by exploring the challenges of such a public theology for justice, peace, and the integrity of creation.