Luther's doctrine of the two kingdoms has often been misunderstood and misrepresented, being treated as if it were the same concept as the separation of church and state. Steven Ozment, in his work A Mighty Fortress: A New History of the German People, offers some much-needed perspective on the subject, as noted on pages 87-88.
For Luther the German problem of the sixteenth century was the devil’s success in tempting both rulers and clergy, subjects and laity, to sell their souls and shirk their moral and spiritual duties. The politicians did so by permitting injustice and obstructing the Gospel; the ecclesiasts by false assurances of salvation and improper secular ambition; and the general run of humankind by allowing itself to be so easily fooled and cowed by both.
In addition to a foreign, predatory papacy, two other enemies were seen to threaten civic society in the early decades of the Reformation: Catholic rulers who suppressed Protestant religious reforms, and renegade Protestant gospelers and revolutionaries who urged the common man to take up arms for alleged Christian rights.
In pursuit of his goals Luther, too, fatefully blurred the lines of authority and power he himself had drawn. He did so, first, by inviting the Christian nobility of the German nation, as Christian laity, to take up his cause against an intractable Church. In1523 he commended the example of a lay congregation in the German town of Leisnig for replacing its Catholic priest with a Lutheran pastor or its own choice, praising its action as an appropriate rejection of false “human law, principle, tradition, custom, and habit.” If this was a new ecclesiology, it was also a timely rationalization.
Again, in 1528, after Saxon visitations discovered spotty religious knowledge and scant moral improvement among the laity in the country parishes, Luther exhorted the German princes, again as Christians, to become “emergency bishops.” In that capacity they were to provide the fledgling Protestant churches with the administration, authority, and force required for their proper maintenance and discipline. Despite qualifying clauses, which stressed the princes’ lay status and the exceptional nature of their new powers, that concession set an ominous German precedent.
When, in, in 1523, princes began persecuting Protestants, Luther attempted in vain to put the genie back into the bottle, lecturing them on “what they might not do.” By 1518 German rulers never again — if ever they had — confined their rule solely to body and property. Luther’s weaving together of temporal and spiritual power enabled the new church to survive its infancy and pursue its mission in relative safety. It became a more cooperative state church, empowered and eager to mix large doses of religion into civic life through the new schools, welfare system, and domestic arrangements it helped create.