Scholars such as Porter have argued that one of the lasting implications of Luther’s construction involves a radical separation of temporal authority from man’s goals in the kingdom of God. Further, Porter argues that “Luther’s radical separation of the ‘two realms’ or kingdoms—church authority and temporal authority—and the emphasis placed on the divine source of temporal authority lead to an ‘unqualified endorsement of state power’ and to a greater fear of anarchy than of tyranny.” Lohse rightly points out that Luther never used the term “doctrine of the two kingdoms,” and suggests a rejection of the entire dichotomous construction: “The brief slogan of the doctrine of two kingdoms is also misleading insofar as it conceals the fact that Luther did not restrict his understanding of the secular kingdom to government and the state but rather included all secular functions… This brief slogan also is not appropriate insofar as it is not able to express the complex and varied pattern of practical action of both Luther and Lutherans.”
Heinrich Bornkamm offers an explanation that allows Luther’s doctrine to maintain aspects of both duality and unity. Pointing to Luther’s seemingly ambiguous usage of the term ‘governments’ as well as the more dichotomous sounding ‘kingdom,’ Bornkamm argues that Luther never intended to create a radical division between the spheres of secular and spiritual. For Bornkamm this understanding of Luther’s doctrine of the two kingdoms appears to be three-dimensional, referring to the relationship between medieval church and medieval state, the general relationship of spiritual and secular, and the activity of the Christian, both on his own behalf and for the sake of others. “But these three dimensions are only aspects of one and the same problem: that of the basic relationship between the gospel and the order of this world.” Thus, while there are real differences between the roles of the temporal and spiritual kingdoms, one cannot understand Luther’s full position from only the perspective of two radically separated kingdoms. Bornkamm argues that, “Luther’s originality lies in his combining [the government and kingdom of Christ and the government and kingdom of the world]. Luther thought that the solution to the problem as he confronted it required, on the one hand, the ruthless separation of the world and the kingdom of Christ as well as, on the other hand, the governance of both of them by the will of God according to the two modes of his love.”
While considering the concerns over the potential for the radical separation of church and state it must be understood that Luther’s usage of the terms ‘kingdom of God’ and ‘kingdom of the world’ seem to leave room for Bornkamm’s interpretation. Certainly it must be remembered that for Luther the concepts of ‘kingdom’ and ‘government’ cannot be necessarily separated from one other. One can then understand Luther’s concept of the ‘Two Kingdoms’ to also include facets of a concept of ‘Two Governments,’ both being ruled by God, and thus in some sense both rightly being called the kingdom of God, though in different manners and by different rulers. Using this model to understand Temporal Authority’s oft confusing terminological ambiguity, we will use the term ‘kingdom of the world’ to refer to Luther’s understanding of the role and sphere of the secular and temporal, and the term ‘kingdom of Christ’ to refer to the churchly and spiritual estate. As we will see, using this understanding will provide for an interpretation of Luther’s doctrine that allows for an active form of Christianity within the realm of temporal authority.
 J.M. Porter. Luther: Selected Political Writings. Philadelphia: Fortress Press, 1974. 2.  Ibid., 1.  Bernhard Lohse. Martin Luther: An Introduction to His Life and Work. Trans. Robert C. Schultz. Philadelphia: Fortress Press, 1986. 188.  Ibid., 191-2.  Heinrich Bornkamm. Luther’s Doctrine of the Two Kingdoms in the Context of his Theology. Translated by Karl H. Hertz. Philadelphia: Fortress Press, 1966. 16.  Ibid., 18.  Ibid., 17.