The Universal Church in God's Design, and The Church's Witness to God's Design, the first two volumes written in preparation for the meeting of the World Council of Churches at Amsterdam, are an ecumenical event in themselves. They form the most significant attempt at combined thinking about the nature and mission of the Church that has yet taken place. The stage is now set for a fresh and exhaustive inquiry behind the present divisions among the Churches into a Biblical and Christological doctrine of the Church which may yet knit into a theological unity the agreement of the Churches reached at Amsterdam. After all “the only valid argument for the union of the Churches is theological, a belief that unity is the will of God for His Church, and that the Church as the Body of Christ ought to represent on earth the mysterious unity of the Godhead” (Vol. II, p. 202). The purpose of this essay is not so much to review the actual material presented in these volumes as to face the questions they raise and, if possible, to point the discussion further along the road to that theological unity.