This study of non-official structures, lay and religious, focuses on little known but enormously effective ecclesial organisations. Hundreds of these transnational Christian organisations are involved in global social engagement that includes: Immigration reform; affordable housing; universal healthcare; food security; wage equity. It presents imitable case studies on the international levels such as The International Movement of Catholic Students and The Jesuit Refugee Service and on the national level, such as Network, and local case studies such as homeless shelters and parish soup kitchens. Structures of Grace shows how these church organisations work and why they are one of humankind's best hopes for a better world.