This is from Krauth, page 265 of *The Conservative Reformation*:
In showing that the Augsburg Confession is the Symbol of our time, the Formula of Concord rests its authority on its being "the unanimous consent and declaration of our faith." The private opinion of individuals, however influential, can in no sense establish or remove one word of the Creed of the Church. Any man who, on any pretence, gives ecclesiastical authority to private opinions, is robbing the Church of her freedom. She is to be held responsible for no doctrines which she has not officially declared to be her own.
Add to this, the wise words of Dr. Piepkorn:
The Book of Concord itself indicates that no further creedal statements are necessary. Three and three quarter centuries of Lutheran experience testify to the rightness of this position. (The Sacred Scriptures and the Lutheran Confessions, p. 104)
If there is ANY hope for unity and concord within and between Lutheran jurisdictions, we simply MUST renounce the temptation to insist that others hold opinions that we hold that are that: theological opinions and not the dogmas of our Churches drawn from the Sacred Scriptures and confessed in our Symbols. There is not a single "modern" corruption of the faith against which our Symbols' Confession of the doctrine of Sacred Scripture does not fully resource us.
Half a century ago or so, Sasse pointed out that the problem with Missouri and all the Synods of the Synodical Conference was that they assumed the Symbols and hence unwittingly ignored them. I propose that if Lutherans are going to get their act together when it comes to the thorny questions that confront us, we can do no better than prayerfully calling upon the Holy Spirit to take the Sacred Scriptures to heart as our Rule of Faith and embrace once more the Confession of that Rule which we call the Augustana. Satis est. It really is.