My late wife Mirjam, an ordained minister and doctor of philosophy, often quoted Luther: "Sin lustily." That is how she translated him. Usually it is: "Sin boldly." People interpret Luther variously. Perhaps he was saying that one cannot undo God's grace. Our faith is not to be held in a skittish kind of way. Or perhaps he was saying that one should boldly own the gravity of one's sin. One should not seek to diminish it. Mirjam's translation makes her own interpretation clear. OBSERVATION: Whatever one may think of Luther's quote, it is a problem that Christians read in the Scriptures: "Not by works" (and the like), but typically readmit works to their thinking (on salvation) in some way.