The Book of Concord contains documents which Christians from the fourth to the 16th century A.D. explained what they believed and taught on the basis of the Holy Scriptures. It includes, first, the three creeds which originated in the ancient church, the Apostles' Creed, the Nicene Creed, and the Athanasian Creed. It contains, secondly, the Reformation writings known as the Augsburg Confession, the Apology of the Augsburg Confession, the Smalcald Articles, the Treatise on the Power and Primacy of the Pope, Luther's Small and Large Catechisms, and the Formula of Concord.
The Catechisms and the Smalcald Articles came from the pen of Martin Luther; the Augsburg Confession, its Apology, and the Treatise were written by Luther's co-worker, the scholarly Phillip Melanchthon; the Formula of Concord was given its final form chiefly by Jacob Andreae, Martin Chemnitz, and Nickolaus Selnecker.
The Lutheran Church—Missouri Synod accepts the Scriptures as the inspired and inerrant Word of God, and the LCMS subscribes unconditionally to all the symbolical books of the Evangelical Lutheran Church as a true and unadulterated statement and exposition of the Word of God.
We accept the Lutheran Confessions as articulated in the Book of Concord of 1580 because they are drawn from the Word of God, and on that account we regard their doctrinal content as a true and binding exposition of Holy Scripture and as authoritative for all pastors, congregations and other rostered church workers of The Lutheran Church—Missouri Synod. http://www.lcms.org/lutheranconfessions