Carl E. Braaten. Principles of Lutheran Theology 2nd edition. Minneapolis: Fortress Press, 2007 Chapter 2 “The Confessional Principle” pp. 35-51
The term “confessional Lutheran” used to be a tautology. Braaten points out that ultimately all Christianity is confessional. Lutherans, who identify the Book of Concord as their confessional standard, disagree about the interpretation of these confessions. Braaten discusses the way the confessions understand themselves. They are, above all, unassuming, not saying much about themselves. They are presented as descriptions of reality, not prescriptions. They also rely on the Bible as their authority.
How then do we use the confessions? They may well be viewed as a compass, orienting us to the central issue of salvation by grace through faith. That concept has, in many cases, been subordinated to other issues. Modern theology tends to leave it behind. Yet the Lutheran confessions are steadfast in their affirmation of this as the central doctrine upon which all others must depend. This is our confessional principle, part of what makes Lutherans Lutheran.