On the basis of Martin Luther’s theologia crucis in the Heidelberg Disputation (1518), the Lutheran concept of law in the 20th Century is examined. Luther’s distinction of religious and civil dimension of law with its religious restriction to a convicting function regarding the sin is received in the Luther-Renaissance of the 1920 and 1930s. The sample of Emanuel Hirsch (1888–1972) gives insight into the deeply ambivalent character of the Lutheran concept of law before World War II which combined a profound theory of Christian subjectivity with a theory of state promoting German nationalism in opposition to western democracy. The moderate theology of Wolfgang Trillhaas (1903–1995) reflecting the experience of the Nazi-Regime de-potentializes the Lutheran prejudice against the law in order to achieve new democratic perspectives on the notion of law in dogmatics and ethics. Thus, an affirmative position is established despite a remaining ambivalence in contemporary Lutheran Protestantism.