Martin Luthers legacy is a very complicated topic. The remembrance is often dubious in my opinion. For example in 2017 (remembering the 1517 thesis announcement by nailing it to the church door - if that event did happen) the head of the reformed churches organisation of Germany, Margaret Käßmann drew a line from Luther to the Enlightment and French Revolution.

Obviously that could be considered a one sided view and in parts of Southern Germany but also among quite a few scientists Luther is seen quite less positive. Richard Marius, a biographer of Luther, stated that though he can be considered to be the most influential prophet since Mohammad he was a catastrophe for Western Civilisation.

Some views which he tells are:

Luther was a religious fundamentalist. He denounced reason as being „the devils whore“. He hated philosophy which detracted from the bible and - according to some philosophers like Richard D. Precht did for the most part simply fail to understand the scholastic philosophy of his time (for lack of education and trying).

Luther declared Kopernikus model to be nonsensical and disproven by scripture. And let not get me started about the anti-semitic views or his role in politics. Or him being a proponent of witch hunting. Oh and also his views on women.

However my sons (who is a Protestant) textbook in elementary school made Luther into a kind of super hero. His teacher would in a test award high grades for answers which stated that Luther ended belief in superstition or made all the world (!) a place of reason and was a man of peace and the greatest thinker of all times.

Now I’m a catholic from the south west of Germany, from a village that was split in half between catholic and Protestant people. One of my grandmas was Protestant. I’m also a very lapsed catholic. But views among my peers was divided along the lines of religion.

Catholics when I grew up in the 1980s and 90s simply didn’t care much about Luther. If you asked about a historic figure from that time it was most likely Gutenberg that would be mentioned. On the other hand Protestants would sometimes tell you about that great guy Luther we catholics weren’t told about because he embarassed the Catholic Church.

In school Luther was shown as a dignified, important and moral person which argued with the church, wanted its reformation and was disappointed by the schism he created. That was, in my opinion, as wrong as the super hero stories my son was told.

Regarding the national identity: the main role that can be attributed to Luther here is his partial role in setting up the formal modern German language - which is something even educated catholics usually grant him.