Martin Luther declared of the person ignorant of the distinction between Law and Gospel that “you cannot be altogether sure whether he is a Christian or a Jew or a pagan, trans. by Theodore G. Tappert, (New York: Harper & Bros., 1938). p. 114.

“Sin is not canceled by lawful living, for no person is able to live up to the Law. Nothing can take away sin except the grace of God.”

Elsewhere he wrote, “whoever knows well this art of distinguishing between the Law and the gospel, him place at the head and call him a doctor of Holy Scripture.”

Tullian Tchividjian writes, “The law, to paraphrase Luther, is a divinely sent Hercules sent to attack and kill the monster of self-righteousness—a monster that continues to harass the redeemed. Christians, in other words, need the law to regularly reveal that we are worse off than we think. We need to be reminded that there is something to be pardoned even in our best works and proudest achievements.

But then, once we are recrushed by Law, we need to be reminded, in the words of an old hymn, that ‘there is a fountain filled with blood drawn from Emmanuel’s veins, and sinners plunged beneath that flood lose all their guilty stains.’ We need to hear that the sins we cannot forget, God cannot remember, or as another old hymn puts it, that ‘though th’ accuser roar, of ills that I have done, I know them well and thousands more; Jehovah findeth none.’ We need to hear over and over that there is no condemnation for those who are in Christ Jesus, that nothing can separate us from God’s love, and that Christians live their lives under a banner that reads, ‘It is finished.'”