It fell to me to decide how to teach Martin Luther in our experimental Freshman religion course, so I adopted a viewpoint that focused on Luther's text
"On the Freedom of a Christian." I've never been super-familiar with Luther, although I've lately been interested in his theology of preaching. I chose "Freedom of a Christian" for class because it seemed the shortest major text I could find, and I remembered reading it for Amy Laura Hall's Christian Ethics course at Duke.
When I picked the text, I had forgotten (maybe I should have payed more attention in Christian Ethics) that "Freedom of a Christian" is the major focus for the "Finnish school" of Luther interpretation. This "school," which now has adherents from theologians like Robert Jenson, finds a more "Catholic" (specifically more "Orthodox") Luther through similarities between his discussion of union with Christ and the idea of "theosis" or divinization in Eastern Orthodox theology.
From my reading, Luther's work here describes a "union" or "mystical marriage" between the believer and Jesus Christ that makes the believer a sharer in Christ's nature and benefits. Faith in the preached word of the Gospel makes this union possible, through the indwelling of the Holy Spirit. This union not only confers justification before God, but it also - importantly for the "Finnish School" and other recent Lutherans - begins a process of sanctification and "divinization" through which the believer is conformed to Jesus Christ.
What follows is a modification of some introductory words I provided to my students on this text and on this topic:
Luther’s message in this reading is that this freedom in Jesus Christ is freedom for Christians to more deeply love their neighbors in more radical ways.
“A Christian person is the most free lord of all, and subject to none; a Christian person is the most dutiful servant of all, and subject to every one.” This phrase is the outline of the entire work. Luther’s Freedom of a Christian is a meditation on “freedom” in the Bible, along with some rigorous theological thinking on faith and love and the behavior of Christians in the World.
Freedom of a Christian is roughly in two parts. The first part talks about faith and law and Gospel in a way that those who know about Luther will not find surprising. But the second half of "Freedom of a Christian" has to do with what Luther calls the “outward man,” and here we have some of the thoughts that set Luther in this text apart from some caricatures. This second half relates to where Luther says that a Christian is “
the most dutiful subject of all, and servant to every one.” How could this not contradict the first part, about the Christian’s freedom from works in faith? Luther’s explanation, as you will see, is that good works naturally follow from faith. Although Luther stresses in the first part that good works cannot justify human beings before God, he says in the second part that a faith that does not overflow into good works is not a real faith.
The freedom the Christian has is freedom thereby to spend their lives in service to God and to their neighbors.
This freedom in service, though, is not merely about being a good person, but for Luther it comes about through a
mystical union with Jesus Christ that happens when the believer has faith. The love or service we give our neighbors is only possible through our souls being united to Jesus Christ through faith. Luther says that Christians become a “sort of Christ” through faith, and that in imitating Jesus through their care for one another, Christians become a community where Christ is in all. Luther is able to put this point very elegantly in saying, “[we ought] freely to help our neighbor by our body and works, and each should become to other a sort of Christ, so that we may be mutually Christs, and that the same Christ may be in all of us; that is, that we may be truly Christians.”