Protestantism was a Reformation, that is to say, a renewal, as regards the core of the matter, as regards religion, and consequently as regards the doctrine of salvation. That may be shown in the main in three points.
In the first place, religion was here brought back again to itself, in so far as the Gospel and the corresponding religious experience were put into the foreground and freed of all alien accretions. Religion was taken out of the vast and monstrous fabric which had been previously called by its name—a fabric embracing the Gospel and holy water, the priesthood of all believers and the Pope on his throne, Christ the Redeemer and St. Anne—and was reduced to its essential factors, to the Word of God and to faith. This truth was imposed as a criterion on everything that also claimed to be “religion” and to unite on terms of equality with those great factors. In the history of religions every really important reformation is always, first and foremost, a critical reduction to principles; for in the course of its historical development, religion, by adapting itself to circumstances, attracts to itself much alien matter, and produces, in conjunction with this, a number of hybrid and apocryphal elements, which it is necessarily compelled to place under the protection of what is sacred. If it is not to run wild from exuberance, or be choked by its own dry leaves, the reformer must come who purifies it and brings it back to itself. This critical reduction to principles Luther accomplished in the sixteenth century, by victoriously declaring that the Christian religion was given only in the Word of God and in the inward experience which accords with this Word. In the second place, there was the definite way in which the “Word of God” and the “experience” of it were grasped. For Luther the “Word” did not mean Church doctrine; it did not even mean the Bible; it meant the message of the free grace of God in Christ which makes guilty and despairing men happy and blessed; and the “experience” was just the certainty of this grace. In the sense in which Luther took them, both can be embraced in one phrase: the confident belief in a God of grace. They put an end—such was his own experience, and such was what he taught—to all inner discord in a man; they overcome the burden of every ill; they destroy the sense of guilt; and, despite the imperfection of a man’s own acts, they give him the certainty of being inseparably united with the holy God: