Some hundred years from inception, the ecumenical movement is stagnating. William C. Ingle-Gillis argues that the problem lies in modern ecumenism’s treatment of denominational Churches as provisional entities requiring reunion to be more fully Christ’s Body. In a work unique both to ecumenical studies and to trinitarian theology, the author redefines ecclesial life from the premise that God’s essence is personhood-in-communion and that the ultimate calling of human persons is to share as fully in the divine life as Christ himself. Concluding that the Churches are, by the Spirit’s...