The Unaltered Augsburg Confession and the Book of Concord Holy Trinity along with the Evangelical Lutheran Church in America [ELCA] of which it is a member, "accepts the Unaltered Augsburg Confession as a true witness to the Gospel, acknowledging as one with it in faith and doctrine all churches that likewise accept the teachings of the Unaltered Augsburg Confession." This church also "accepts the other confessional writings in the Book of Concord, namely, the Apology of the Augsburg Confession, the Smalcald Articles and the Treatise, the Small Catechism, the Large Catechism, and the Formula of Concord, as further valid interpretations of the faith of the Church." The Augsburg Confession The Augsburg Confession remains the most authoritative confession of faith for world Lutheranism. It was presented to Emperor Charles V of the Holy Roman Empire on 25 June 1530 as a summary of the faith held by a group of princes and city-states who were supporting Martin Luther's understanding of the Gospel. The Unaltered Augsburg Confession The Unaltered Augsburg Confession. The 1530 Augsburg Confession, slightly revised in 1531, became the key document in the 1580 Book of Concord, and is generally known as the "unaltered" Augsburg Confession The Altered Augsburg Confession. In 1540 Philip Melanchthon revised the Confession to bring key teachings, especially on the Lord's Supper, closer to the views held by Reformed Protestants. This 1540 version is called the Altered Augsburg Confession. The Book of Concord The Book of Concord is the classic, authoritative confessional statement of much of Lutheranism, compiled at the end of the 16th century in response to both Catholic and Reformed confessions. It contains Preface (1580) The Three Ecumenical Creeds [Apostles', Nicene, and Athanasian] The Augsburg Confession (1530) [the "unaltered" version of 1531] Apology of the Augsburg Confession (1531) [written by Philip Melanchthon] The Schmalcald Articles (1537) [written by Martin Luther] Treatise on the Power and Primacy of the Pope (1537) [written by Martin Luther] The Small Catechism (1529) [written by Martin Luther] The Large Catechism (1529) [written by Martin Luther] Formula of Concord (1577) The Book of Concord is not accepted in full by all Lutheran churches. The Augsburg Confession and the Book of Concord in English The best current English translation of the Book of Concord is The Book of Concord: The Confessions of the Evangelical Lutheran Church. Edited by Robert Kolb and Timothy J. Wengert. Minneapolis, MN: Fortress Press, 2000. It includes the unaltered Augsburg Confession.