Book excerpt: Visible unity means that churches recognize in one another a witness to the fullness of the apostolic faith which they profess. Will Christians be able one day to declare together before the world, in common confession and praise, their faith in who God is and what God has done? This text-growing out of many years of study and consultation, involving theologians from various Christian traditions and from all parts of the world-is a unique instrument for drawing the churches toward such a common confession. As a contemporary explication of the creed that emerged from the ecumenical councils of Nicea (325) and Constantinople (381) and is used in both Eastern and Western Christian liturgies, Confessing the One Faith relates the subject matter of those ancient affirmations to the challenges of today's world-in which the language and philosophy of the fourth century sound alien to many, and the basic affirmations of the Christian faith are widely questioned. This new edition includes an introduction written by Dame Mary Tanner, a president of the World Council of Churches.