What I want to do in this chapter is to convey the structure of Lutheran thought. One could of course do this in the abstract, as an ‘ideal’ system of thought, drawing on numerous Lutheran theologians by way of illustration. I have decided however that this would unnecessarily complicate the chapter and that it is preferable simply to turn to Luther as the progenitor of a tradition, leaving the discussion of later Lutheran theologians considered in their own right to subsequent chapters. I shall however draw on a whole variety of Lutheran commentators on Luther, thereby conveying something of a wider tradition, indeed of different schools of Lutheran thought and divergent emphases. Catholics, as we shall see, have too often treated Luther as though he were a ‘one-off’, his thought the result of some personal problem or disposition. On the contrary, Luther was the founder of a vibrant tradition, one way of structuring Christian belief. I shall make one exception to this policy of confining myself to Luther and those who commentate directly on Luther. I shall at points make reference to the thought of Dietrich Bonhoeffer. I do this both because I do not consider Bonhoeffer elsewhere (and he seems important) and also because no one more markedly than he took up and translated Lutheran insights, expressing them in other form. I believe that reading Bonhoeffer gives one insights into Luther and not simply vice versa.