The United Church of Christ was formed in 1957 to be first and foremost a proactive agent in the often tangled but nonetheless breathtaking ministry and mission of ecumenicity in the pursuit of ever greater visible unity among the diversity of Christian churches. This singular task of ecumenicity is arguably the most crucial in the formulation of an ecclesiology essential to the United Church of Christ as a "united and uniting" church; a mission Albert Walsh refers to in this book as her God given "vision-and-vocation." In United and Uniting, Walsh contends that the identity and self-understanding of the UCC at both national and local levels is best comprehended as a "Christ-centered" and "conciliar" fellowship, and therefore her ecclesiology must be fundamentally ecumenical. A Christ-centered ecumenicity must shape, inform, and characterize the whole of her ecclesiology, and membership in the UCC is defined almost exclusively in terms of a "conciliar" identity. Walsh advocates a return to ecumenical formation at the level of the grassroots or membership in the local congregation as holding the greatest promise for furtherance of the wider ecumenical mission.