The first part of the Book of Concord has the title "The Three Chief Symbols." These symbols are the three ancient creeds of the church - the Apostle's Creed, the Nicene Creed, and the Athanasian Creed. There are tons of great books written about these creeds so I'm not going to go into a great deal of detail about them. However there uses by the Lutheran Reformers is very important.
The Lutheran reformers went to great lengths to demonstrate that they were not breaking with the traditional faith of the church, only its excesses in structure, power, and tradition. In fact, Luther and the other reformers saw themselves as stripping away 1500 years of accumulated human tradition and returning to a more authentic Biblical faith. Think of it like striping off all that ugly paint people put on their beautiful oak woodwork during the ‘70s. (Lime green and orange! What were we thinking?) This stripping away of accumulated baggage is a never ending task and why some people like to say the reformation is never over because the Church is in constant need of reforming.
By including these three Creeds the Reformers were stating that the very foundations of Christianity are contained in them. If a person rejects these creeds and what they say they are rejecting the accepted and universal definition of what Christianity is. When this happens we do not even have a common place to begin our conversations about what differences we might have.
