The early twenty-first century has dashed hopes for a more peaceful, harmonious, and prosperous world order as many societies have been plunged into conflict and living conditions for many have become ever more precarious. The crisis is compounded by the advance of damaging climate change that jeopardizes the future of life on earth. Where can the imagination be found to meet such an unprecedented crisis? This book mines one hundred years of ecumenical reflection on mission, affirming the strengths of this tradition. It does so in a spirit of metanoia (repentance), recognizing that churches and missions were often complicit in trends that have proved to be damaging. At the same time, it draws on elements of renewal in thinking about mission--cherishing of life, environmental responsibility, action for justice, deepening of spirituality, working from a basis in ecumenical Christianity to make common cause with people of all faiths and convictions who share similar concerns. While the book is unflinching in confronting the injustice and destructiveness of the prevailing world order, its final message is one of hope, proposing that a retrieval and renewal of the ecumenical vision holds the promise of a brighter future.