Martin Luther taught that the Bible—both Old and New Testaments—consists of two sorts of writings: law and gospel. He regarded as gospel the parts of the Bible that were directly conducive to salvation. The rest he regarded as law, as an unnecessary burden and an obstacle to salvation.
Luther found law and gospel intermixed in both the Old and New Testaments: In the Old Testament, Genesis was gospel because Abraham was saved by his faith, but books such as Esther were merely law. In the New Testament, the letters of Paul were gospel, but the letter of James was an “epistle of straw.”1 This contrast between law and gospel is akin to Paul’s distinction between works and faith. Only the latter is essential to salvation.