Many modern-day revisionists of the Reformed heritage are on a quest to distance the Reformed and Lutheran traditions from one another. I’ve even heard the claim that there is a Reformed doctrine of justification and then a Lutheran one. This is quite strange, since Luther and Zwingli only differed over the doctrine of the Lord’s Supper, and the Reformed happily signed the Augsburg Confession (Variata), which only differed from the Lutheran version (Invariata) on the point of the Lord’s Supper.
Reformed revisionists often cry out, “Lutheran!” when someone distinguishes between Law & Gospel. If you didn’t know that Zacharias Ursinus, author of the (Reformed) Heidelberg Catechism, wrote the following, you could think it was penned by Luther himself.
… there is a great difference between the law and the gospel. They differ,
1. As to the mode of revelation peculiar to each. The law is known naturally: the gospel was divinely revealed after the fall of man.
2. In matter or doctrine. The law declares the justice of God separately considered: the gospel declares it in connection with his mercy. The law teaches what we ought to be in order that we may be saved: the gospel teaches in addition to this, how we may become such as the law requires, vis: by faith in Christ.
3. In their conditions or promises. The law promises eternal life and all good things upon the condition of our own and perfect righteousness, and of obedience in us: the gospel promises the same blessigns upon the condition that we exercise faith in Christ, by which we embrace the obedience which another, even Christ, has performed in our behalf; or the gospel teaches that we are justified freely by faith in Christ. With this faith is also connected, as by an indissoluble bond, the condition of new obedience.
4. In their effects. The law works wrath, and is the ministration of death: the gospel is the ministration of life and of the Spirit. [Commentary on the Heidelberg Catechism, 497-98]
There are surely differences in the Reformed and Lutheran traditions, but let’s not pit them against one another, as if there were no overlap. We must also be wary of making the Reformed tradition into our own image, which can be prevented in large measure by reading the original sources. Justification by faith alone was a common doctrine to the confessional Protestants as was the distinction (not separation!) between Law & Gospel. What God demands of us in His justice (Law), He provides for us in our Mediator, Jesus Christ (Gospel).