Warning: This is not an attack on the Lutheran denomination.  It is merely a collection of my questions and disagreements with some of the teachings found in a book I read, summarizing the Book of Concord, which is a pillar in commonly held Lutheran doctrine.  I know many Godly men in the Lutheran branch of the Church who I respect deeply.  Take these as food for thought and perhaps a challenge to delve into your own convictions to see them without prejudice, regardless of your spiritual background.  I do not seek an argument or any more division in the Body of Christ; there is far too much of that already.
Mainly my reaction to reading:
Preus, Robert; Getting into The Theology of Concord (A study on the Book of Concord); Concordia Publishing House, St. Louis, Missouri; 1977.
Book of Concord includes:
Creeds and formal confessions from 2nd to 6th centuries (before the Reformation)
Luther’s Small and Large Catechisms (1529) –written as a summary of our faith
Augsburg Confession (1530 by Philip Melanchthon) define German Protestantism
Apology of the Augsburg Confession (1531 same author) –defend 1530 statement
Smalcald Articles (Luther’s confession in 1537)
Treatise on the Power and Primacy of the Pope (Melanchthon in 1537)
Formula of Concord (1577) Lutheran theologians settling disputes
Book of Concord assembled in 1580
The confessions are said to be the symbols that right and perfect doctrine is possible and essential to Christian life.  All those who will go with to serve the Lutheran church subscribe under oath to these Lutheran confessions (Unconditional subscription – C.F.W. Walther, father of Missouri Synod p15).  They claim that they will not ‘militate against Scripture’ in any major or minor point with no mental reservations.  Do all confirmation classes take an oath or something concerning them?  If these great theological issues are to be sworn to by someone younger than I, where is the room for the Spirit to teach?
^I find that Paul made allowances for differing convictions (in one specific instance Rom 14-15).  While there is a perfect doctrine, it was said that if a man has a conviction to not eat meat (which is not perfect doctrine) then it is sin for him to do so and that others near him should consider their love for their brother first and their scripturally provided freedom secondary.
I admire the attempt to follow I Cor. 1:10 and have no divisions.
^Upon reading further I discover that the divisions are not mentioned to be doctrinal, but in some claiming to follow Paul, Apollos, Peter, or Christ.  He does not go on to say that one doctrine is superior or perfect, but to concentrate on preaching the gospel.
There is a good point by Lutheranism that a common spirit is less stressed when there is a agreement “in doctrine and in all its articles and … the right use of the holy sacraments”.
^I believe the answer lies in “great patience and careful instruction” rather than excommunication and “The opinions of the erring party cannot be tolerated” (p18).
Sola Scriptura is a stud statement and ‘the fathers’ were right to say that everything should be weighed against scripture.
^I believe this to be a personal principle however.  If members of the church are to be held in oath to the confessions in The Book of Concord rather than what they have learned or seen for themselves in scripture isn’t that “going beyond what is written”?  Even if the confessions are perfect, a person should not be expected to make ‘unconditional subscription’ to extra-gospel ideas unless they’ve spent the study and prayer to come to those conclusions themselves.
I do find most of the doctrines set forth in these confessions to be very agreeable.  It is not in my authority to make a judgment, but I can make a statement because it is in accord with my understanding of scripture.  My primary disagreement is in the weight laid on these documents today by some people.  Everything excellent or praiseworthy in The Book of Concord originated in the Bible.  Therefore it is my conclusion that the work of Luther, Melanchthon, and the others should be taken as what I would expect to be the intent of these Godly men: Commentary, instruction, and apology of our faith in Christ.
As the believers in Acts did not even have the New Testament writings, much less the confessions and doctrine of those to come, it is my conviction that the Gospel message is the only doctrine worth pledging our unconditional faith in.  And that Gospel as repeated by the Old Testament scriptures, the recorded words of Jesus, and the writings of Paul, John, Peter, and the rest of the New Testament is this:
That the Son of Almighty God would be born on earth; that he would suffer many things; and die in our place as an atoning sacrifice for our sins.  In three days He would rise bodily from the dead and return to the right hand of Father in heaven as Lord of all.
That if you confess with your mouth, “Jesus is Lord,” and believe in hour heart that God raised him from the dead, you will be saved.  For it is with your heart that you believe and are justified, and it is with your mouth that you confess and are saved. –Rom 10:9-10