All Christendom, Catholic and Protestant, believes that God has spoken to men, and that his Word thus spoken is the Word of Life, the good news of salvation. All Christendom too, though not without reservations, believes that the Scriptures of the Old and New Testament contain that Word written. Beyond this Christians begin to part company along a hundred different roads. The cause of their divergence is the variety of different answers given to the question how God’s Word written is to be understood. Is it self-authenticating j does it yield its meaning to each man’s conscience by the inner light of the Spirit, or are we to approach it by the aid of sound learning, relying only, for the conviction of faith, on the ordinary means of knowledge with which reason has endowed us? What part does the concept of the Church play in mediating God’s message to men’s minds, in terms which they can depend upon with certainty? Does God, in his written Word, stand in judgment over and reform the verdicts of the Church, or does Christ our Lord, living in it by the power of the Holy Spirit, guide its understanding of the written word and himself speak with its voice? If the Church is integrally necessary to the proclamation of the gospel, what is its nature and how can its voice be recognised and its verdicts guaranteed? The fundamental disunities of Christendom lie in the answers given to these questions. To the finding of a way which will lead from such diversity into a unity willed by God the world-wide ecumenical movement has addressed itself for over thirty years with a sincerity and depth of desire which must surely be the work of the Holy Spirit.