This will be a rather short post, but I think that the topic deserves it own blog post.
Not long ago a Roman Catholic friend of mine posted something about Mary on their Facebook wall, whereupon some Lutheran friend of his replied that the honouring of Mary was one of the things that Luther reacted against. The problem was, of course, that his claim was in fact not true.
Luther had an immense devotion to Mary, as Roman Catholic apologist Dave Armstrong points out. Luther held that Mary was/is perpetually virgin, that she was/is the mother of God (in Greek, Theotokos, ‘God-bearer’), and (perhaps more surprisingly) that she was born pure. Here I just want to point out that these beliefs are not only Luther’s personal belief but also part of the wider Lutheran tradition.
We don’t find this explicitly in the core of the Lutheran confessions, i.e. the three ancient creeds (the Apostles’ Creed, the Nicene Creed, the Athanasian Creed), Confessio Augustana, and Luther’s Small Cathechism. But we do find it in Luther’s Smalcald Articles, which is part of the Book of Concord, and thus part of the wider tradition of the Lutheran confessions (binding in, for instance, the LCMS).
In most english translations of the Smalcald Articles, I.IV it states, amongst other things, that «the Son became man in this manner, that He was conceived, without the cooperation of man, by the Holy Ghost, and was born of the pure, holy [and always] Virgin Mary.» See here, for instance. Here we see reflected the three doctrines mentioned above: Mary is the mother of God, as Jesus is God. But more importantly, the confession states that she is both pure and always virgin.
It has been pointed out to me that the belief in the perpetual virginity of Mary is not in all versions of the Smalcald Articles, and it wasn’t part of Luther’s original German version. One person said that «this is why good editions of the Book of Concord put it into brackets (‘was born of the pure, holy [and always] Virgin Mary’).» The problem is that I think this person has misunderstood the use of the brackets. They are not there to put the concept into question, but to signify that there is a difference, though not a contradiction, between the German and the Latin versions.
The German text says von der reinen, heilegen Jungfrauen Maria geboren sey (‘from the pure, holy Virgin Mary [he was] born’). The Latin text, however, says ex Maria pura, sancta, sempervirgine nasceretur (‘from Mary; pure, holy and avways virgin he was born’). The edition I use is Die Bekenntnisschriften der Evangelisch-Lutherischen Kirche, ed., Irene Dingel (Vollständige Neuedition. Göttingen: Vandenhoeck & Ruprecht, 2014). This is not just a ‘good edition,’ it is the very best.
The reason many translations of the Smalcald Articles (at least, as far as I’m aware, in English, Norwegian, and Swedish) put the words ‘and always’ in brackets is because they don’t bother to make two separate translations, one of the German, and one of the Latin. Therefore, to mark that there is a difference between the two, many translations puts ‘and always’ in brackets. As I’ve already said, it isn’t there to put the concept into question. The Latin text, including sempervirgine is part of the official text of all those churches which hold to the Smalcald Articles, even if Luther didn’t originally include it in the German edition. He wasn’t infallible, and official confessions ‘belong’ to the community, not just the author. Melanchthon, for instance, didn’t ‘own’ Confessio Augustana (and thank God for that). The churches in question includes the LCMS, as evidenced from the fact that ‘always virgin’ is part of the text included on their website. Yes, it is in brackets, but that doesn’t mean that they don’t hold to it. It is merely to point out that there is a difference (though not a contradiction) between the two official texts. Semper Virgo or sempervirgine is part of the Lutheran tradition.
So no, the proper honouring of Mary was one of the things that Luther reacted against.
 These are the only five confessions that are binding on all Lutherans, and thus, in my estimation, the only thing, in addition to Scripture, you need to hold to call yourself a ‘confessional Lutheran,’ though many (mostly Americans) would disagree. But when the Formula of Concord was written, in 1577 (in German, translated into Latin in 1584), it was rejected by the Lutherans in Hesse, Zweibrücken, Anhalt, Pommeranian (Land), Holstein, Denmark (Denmark-Norway), Sweden, Nürnberg, Strassburg, and Magdeburg. The Formula of Concord has never been a universally accepted document. A document doesn’t automatically become a binding confession just because a Lutheran theologian writes it.
 The LCMS holds to the entire Book of Concord.