One of my favourite blogs these days is Martin Yee, a Singaporean Lutheran. Here is something to put in your theological pipe from his recent digest of a Philip Cary article:
Augustine gives us the gist of the prayer for grace in a famous formulation that irked Pelagius: “Give what you command, and command what you will.” To bring the difference between Luther and Augustine into focus, we can contrast this prayer with a formulation in Luther’s treatise, The Freedom of a Christian (1520): “The promises of God give what the commandments of God demand”. This formulation both echoes Augustine’s prayer for grace and replaces it with something new. Instead of human words of prayer, it draws our attention to the divine word of promise, which Luther elsewhere calls by the name “Gospel.” The distinction he draws in this treatise between commandments and promises as the two types of the Word of God is clearly the same as the distinction he draws elsewhere between Law and Gospel. The crucial point about the Gospel promise is always that it gives what it promises to those who believe it. So for Luther faith does not mean praying for grace and righteousness, but obtaining them by taking hold of Christ in the Gospel.