Luthers transformational idea of justification by faith alone was often misunderstood and misrepresented in the early years of the Reformation. In 1520, with his Wittenberg congregation in mind, Luther set out to clarify the biblical foundation of good works. In doing so he recast the very definitions of sacred and secular both for his own generation and ours.

Scott H. Hendrix is Professor Emeritus of Reformation History and Theology at Princeton Theological Seminary. He earned a PhD in Reformation studies from Tubingen University in Germany, and has chaired the Continuation Committee of the International Congress for Luther Research. Among his many publications are Luther (2009) and Martin Luther: A Very Short Introduction (2010).