If, according to Lutheran teaching, the law is not made for a righteous person, if it has reference only to sin, then it had no place in the state of created, original righteousness. Man in the holy divine image was without the law. His condition is thought of as the perfect unio mystica, the gracious indwelling of the most holy Trinity. The command not to eat is therefore only something negative and does not come under the concept of law. It was only a pedagogic measure in the interest of confirming the state of innocence. It also gave man opportunity, however, to enter into sin and so into the position of being under the law.
According to the Reformed, on the other hand, the first man was under the law just like the believer. For the former, too, the objective, divine will existed as a norm outside himself, according to which he was obligated to live and conduct himself. After all, the necessity of a progressive development into perfection was facing him. Such perfection he had not yet received with the divine image, but it was intended for him. Even as a bearer of the divine image Adam was subject to the prescriptive dictates of the law in the form of a commanding conscience, which in this form constitutes an essential motivating element of human nature. For human nature is simply the finite, which can get to know the divine will as the absolute only in this form. The purely finite sees the infinite opposite it and sees itself only as different from and dependent on it.
Lutherans, by way of contrast, see Adam as the final product of God’s creation, who did not need any real development but only to persevere and be confirmed in holiness. Enjoying the most intimate unity with God by virtue of the indwelling of the Trinity, he was the perfect human model. Because he was created with perfect righteousness, the difference between what one should do and what one wants to do, between God’s will and his own will, did not even exist. God’s will was expressed only as that which was identical with man’s will. Man’s will was in full conformity with God’s. That a separation occurred between the two and the consciousness of the divine will became a reality as a demanding conscience is already the result of sin.
The imperative form of the divine will in the conscience became a reality only then when God had to call man to account and condemn him. It is, however, no more essential than the form whereby God called man to account and condemned him and is only a testimony to the already degenerate quality of human nature. Rather, only that original holy impulse which was at the bottom of that divine commanding is shown to be essential; this is not law, not duty, but willingness, love. And this is restored from the categorical imperative form through the indwelling of the Holy Spirit, by faith. It was only when the Reformed idea of a covenant of works and a covenant of grace was adopted that Lutheran teaching began to abandon this view, which originated from exegetical considerations.
Matthias (Max) Schneckenburger, “Vergleichende Darstellung des lutherischen und reformierten Lehrbegriffs” (A Comparative Presentation of the Lutheran and Reformed Concept of Doctrine), quoted in “The Difference Between The Reformed And The Lutheran Interpretation Of The So-Called Third Use Of The Law” by August Pieper. All italicized print appears in Pieper’s essay.