The Book of Concord by Various Theologians

From the Overview of the Book of Concord, "The Book of Concord contains documents Christians have used since the fourth century to explain what they believe and teach on the basis of the Holy Scriptures. First, it includes the three creeds that originated in the Ancient Church: the Apostles' Creed, the Nicene Creed, and the Athanasian Creed. Second, it contains 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 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 Nicholas Selnecker."

Confessional Lutherans believe these confessions in the Book of Concord are a correct exposition of the Scriptures. So, it's a pretty important book! It is awesome to read and re-read the confessions and see how clearly articulated all the doctrines are. Evey time the Book of Concord is read, something new can be gained or something significant can be reinforced.