Sola Fide

Luther's own account placed the turn in his reading of Romans 1:17, where the righteousness of God ceased to be the standard by which he would be judged and became the righteousness God gives. From that reading followed a distinction he treated as the hinge of everything: the law shows a person what is owed and cannot supply it, while the gospel announces what has been supplied. Justification is therefore not a process a believer completes but a verdict already pronounced, received by the empty hand of faith.

Melanchthon gave the position its confessional form in 1530. Article IV of the Augsburg Confession is four sentences long and states that people cannot be justified before God by their own powers, merits or works, but are justified freely for Christ's sake through faith, when they believe that they are received into favour and that their sins are forgiven on his account. The vocabulary is deliberately forensic, drawn from the law courts rather than from medicine: righteousness is imputed, reckoned to the believer's account, not infused into them as a quality that grows.

The Reformers were careful about the objection they knew was coming, that a verdict without change licenses whatever the believer pleases. Their answer was that faith is never alone even though it justifies alone, since the faith that receives Christ receives him whole and cannot receive him without being remade. Good works are the fruit that follows and the evidence that faith is real; they are simply not the ground of the verdict.

The Council of Trent addressed justification in its sixth session in January 1547, and the decree is longer and more careful than Reformation polemic usually allowed. It affirms that nobody merits the grace of conversion, that grace is a free gift, and that no one can be justified without it. Where it parts company is on what happens next: Trent holds that grace genuinely makes a person righteous rather than merely declaring them so, that the righteousness received can increase, and that a justified person cooperates with grace in works that are truly meritorious because grace makes them so.

The canons attached to the decree then condemn the alternatives one by one, including the proposition that the sinner is justified by faith alone, understood as excluding the necessity of preparation and cooperation. Each side read the other's position through its own vocabulary, and the words merit, faith and righteousness did not mean the same things across the divide, which is part of why the argument lasted four centuries with so little movement. It moved in the twentieth. Sustained bilateral study of the actual sixteenth century texts led to the Joint Declaration on the Doctrine of Justification, signed in Augsburg in 1999 by the Lutheran World Federation and the Roman Catholic Church, which set out a common understanding of justification by grace through faith and concluded that the mutual condemnations of the Reformation era no longer apply to the partner as now understood. Neither church surrendered its confessional language, and other Protestant bodies were not party to it, but the flashpoint of the Reformation is no longer where it was.