Now we have said before, that the law in a Christian ought not to pass his bounds, but ought to have dominion only over the flesh, which is in subjection unto it, and remaineth under the same. When it is thus, the law is kept within his bounds. But if it shall presume to creep into thy conscience, and there seek to reign, see though play the cunning logician, and make the true division. Give no more to the law than belongest unto it, but say thou: 'O law, thou wouldest climb up into the kingdom of my conscience, and there reign to reprove it of sin, and wouldest take from me the joy of my heart, which I have by faith in Christ, and drive me to desperation, that I might be without all hope, and utterly perish. This thou doest besides thine office: keep thyself within thy bounds, and exercise thy power upon the flesh, but touch not my conscience; for I am baptized, and by the Gospel am called to the partaking of righteousness and of everlasting life, to the kingdom of Christ, wherein my conscience is at rest, where no law is, but altogether forgiveness of sins, peace, quietness, joy, health and everlasting life. Trouble me not in these matters, for I will not suffer thee, so intolerable a tyrant and cruel a tormentor, to reign in my conscience, for it is the seat and temple of Christ the Son of God, who is the king of righteousness and peace, and my most sweet saviour and mediator: he shall keep my conscience joyful and quiet in the sound and pure doctrine of the Gospel, and in the knowledge of this passive and heavenly righteousness.'"

-- Martin Luther in the Introduction to his A Commentary on St. Paul's Epistle to the Galatians as printed in John Dillenberger's Martin Luther: Selections from His Writings.