Peter Leithart quotes historians Luther Peterson and R. Po-Chia Hsia’s contentions that the desire for confessional uniformity (whether Catholic, Lutheran, or Calvinist) in the 16th and 17th centuries helps to explain “he transformation of medieval feudal monarchies into modern states, in particular how the new states changed their inhabitants into disciplined, obedience and united subjects” (Peterson).
His first paragraph of quotation and summary from Hsia puts confessional conformity in context:
“The process of political centralization, discernible in the fifteenth century – the adoption of Roman Law, the rise of an academic jurist class, the growth of bureaucracies, and the reduction of local, particularist privileges – received a tremendous boost after 1550. Conformity required coercion. Church and state formed an inextricable matrix of power for enforcing discipline and confessionalism. The history of confessionalization in early modern Germany is, in many ways,the history of the territorial state.” Confessionalization was largely sponsored by the state, which “usually played a more crucial role than the clergy in determining the course of confessionalization. . . . Having become the head of their territorial churches, princes understood the imposition of confessional conformity both as an extension of their secular authority and as the implementation of God’s work.”
At the same time, this was not an instantaneous process. As Leithart notes (presumably from Hsia’s work), “Even in 1624, in the region around Osnabruck, most of the clergy could not be easily categorized as Lutheran or Catholic.”