In the preface to the Book of Concord the compilers stated that all the writings contained in “this Christian confession, based as it is on the witness of the unalterable truth of the divine Word.” In other words, what follows is a clear and proper understanding of Scriptures and not their opinions.
While the Book of Concord was intended to bring the splintered Lutherans back to unity, Concord means agreement by the way, it had the further goal of protecting against such fracturing in the future. They wished “to warn and, as far as we might, to secure our posterity in the future against doctrine that is impure, false, and contrary to the Word of God.” And later, “that a pure declaration of the truth might be transmitted to our posterity.” They believed that this common confession would help guard against conflict.
The following statement shows that the Book of Concord was not the opinion of one or two people. “Therefore this Christian agreement is called and also is the unanimous and concordant confession not only of a few of our theologians but generally of each and every minister and schoolmaster in our lands and territories.” In other words, this book defines what it means to be Lutheran. If you agree with what it says you're Lutheran, if you don’t you’re not. Every Lutheran denomination since this was written has at least given lip service to this idea.
