Bill Cork posts some tidbits on the Luther movie. One mention (from The Lutheran Witness) is particularly noteworthy:

Doubtless there are also other reasons to revisit the Father of the Reformation—the magnificent realism of his two-kingdoms theology, for example which would bring some sanity to postmodern times.

The “two-kingdoms theology” that the reviewer praises is the teaching that God interacts through the world both through the kingdom of grace – the (invisible) church – and through the kingdom of power – the state. This dovetails with another Lutheran theme – the right division of Law and Gospel. Thus the kingdoms of grace has precious little law (so there’s cheap grace) and the kingdom of power has precious little mercy.

This theology is (1) a foreshadowing of the infamous JFK position that a Catholic’s faith should not inform his performance of governmental duties and (2) a hard habit to break for this former Lutheran.