The rather strange title of this volume, bringing together two adjectives that do not seem to belong together, rests on attempts to explain two Latin concepts that are not expressed by the English words derived from the original Latin. “Aliena” refers in fact to anything that comes from outside while “propria” refers to what is internally produced. When applied to righteousness, as Luther did when he first formulated his revolutionary concept of human identity or righteousness, they refer to the unconditional gift of the identity of child of God bestowed by the Holy Spirit through our faith in Jesus Christ. That faith determines, as Luther explained in his explanation to the First Commandment in the Large Catechism, our core identity, our righteousness before God. The righteousness or identity established through our love for others and our service to all of God’s creation properly comes from our actions, even when they are moved and directed by the Holy Spirit. For Luther, in Latin, the alien and the proper are most distinct and quite inseparable.
Almost forty years ago it fell to me to teach an elective on the theology of Martin Luther at Concordia College in Saint Paul, Minnesota. Luther’s Galatians commentary went onto the required reading list. Luther’s own students counted the commentary on Galatians published in 1535 among his best works. The commentary provided readers an edited version of his lectures delivered in 1531. The shadow of the condemnation of the Augsburg Confession’s doctrine of justification by grace through faith by the Roman Catholic “Confutation” hung over those lectures. Because of its content and its historical situation, the commentary seemed to me to be an excellent way to get my students into the heart of Luther’s thinking. I thought I knew Luther quite well by that time, in my early 40’s, and so was surprised to find that in the preface of the printed commentary, he had written,
This is our theology, by which we teach a precise distinction between these two kinds of righteousness, the active and the passive, so that morality and faith, works and grace, secular society and religion may not be confused. Both are necessary, but both must be kept within their limits. 
In reading the reformer’s exposition of Galatians with this in mind, it became clear how the distinction of zweierlei Gerechtigkeit—it can be rendered either “two kinds of righteousness” as does Luther’s Works,  or “twofold righteousness”—did indeed form and inform Luther’s understanding of how God created human creatures to be in a relationship of trust and peace with him and how he restores that relationship.
I do not know how I had missed that in my earlier study as student and instructor. True, only an occasional modern study had highlighted the distinction,  and Melanchthon’s subsuming the distinction into his topic on justification did not plant it firmly in the minds of Luther’s and Melanchthon’s students as a category of teaching or topic. My instructors had presumed it in teaching justification, and in my student days theological anthropology was not prominent, as it was becoming in the 1980s. Conversations with colleagues in Saint Paul and then a decade later, when Concordia Seminary called me to join its faculty, with colleagues in Saint Louis enriched my own understanding as they developed further explanations and applications of the fundamental framework for Luther’s understanding of what it means to be human.
Melanchthon, too, distinguished between what he preferred to call the righteousness of the law and the righteousness of faith. His Loci communes of 1535 defined “new and eternal righteousness and life” as the “gracious remission of sins freely given” or “mercy and freely given acceptance.” For the gift of righteousness in God’s sight through grace signifies “the giving of the Holy Spirit and eternal life, that is, new and eternal righteousness and life . . .” Melanchthon interpreted John 1:17, “the law was given through Moses, grace and truth were made through Jesus Christ,” with these words: “you have heard the law, but this is not what abolishes sin, and it does not get rid of the blindness in the mind, that is, doubts about God and growling before the judging God. It does not deliver true and eternal righteousness, but [exercises] a deadly external discipline over us. That is the eternal and lasting and perpetual righteousness.”  But that unconditionally bestowed righteousness produces another kind of righteousness, that of “our obedience, that is, the righteousness of a good conscience or works, which God commands us to do, [which] necessarily follow reconciliation.”  This relationship of the righteousness of the law and the righteousness of faith Melanchthon accentuated in the Apology of the Augsburg Confession. 
Somewhere in the 1990s, another passage, this one in the work of the “second Martin,” Martin Chemnitz, struck me. Chemnitz conveyed what Luther’s distinction means with its teaching on “twofold righteousness” in regard to the disputes over justification with Roman Catholics. In his Examination of the Council of Trent he wrote,
For it is regarding the good works of the regenerate, or the new obedience, that there is now the chief controversy between the papalists and us, namely, whether the regenerate are justified by that newness which the Holy Spirit works in them and by the good works which follow from that renewal; that is, whether the newness, the virtues, or good works of the regenerate are the things by which they can stand in the judgment of God that they may not be condemned, on account of which they have a gracious and propitiated God, to whom they should look, on whom they should rely, in whom they should trust when they are dealing with that difficult question, how we may be children of God and be accepted to eternal life. 
Chemnitz contrasted the Roman Catholic answer, which Trent presented as grace-wrought good works that the believer can present to God as proof of righteousness, with his own answer as a follower of Luther and Melanchthon: simply the favor of God, and trust in God’s promise to give forgiveness, life, and salvation for Christ’s sake to his chosen people.
Luther’s anthropological axiom of the twofold righteousness is an integral part of a series of hermeneutical rules that governed his interpretation of Scripture.
Luther confessed God first of all as Creator. As described in Genesis 1, his act and mode of creating of the universe and all reality in it ex nihilo—out of absolutely nothing—provides also a model, according to Luther, for understanding how he goes about the re-creation of sinners into children of God. His steadfast lovingkindness brought the worlds into being without any conditions through his Word, and with this same steadfast lovingkindness he planned and executed the re-creation of those who doubted his Word and defied his lordship. He accomplished this fashioning of new creatures in Christ (2 Cor. 5:17) through the death and resurrection of Jesus Christ, also without any condition limiting God’s love and any contribution required from the human side. 
Luther’s anthropological axiom of the twofold righteousness is an integral part of a series of hermeneutical rules that governed his interpretation of Scripture. It is coordinated with his view of the two words with which God speaks when he approaches sinners. The first is his plan for human performance, which ends up as the foe of sinners. It is the pronouncement of judgment upon them despite its goodness as the blueprint for the fully human life. The second is his plan for human deliverance through the work of Christ. This plan has come to mortal terms with the law’s condemnation of human sin and restores human integrity and identity as child of God to the sinner through the Holy Spirit’s delivery of the benefits of Christ.
In addition, the twofold righteousness and the distinction of law and gospel are coordinated with Luther’s perception of the two dimensions of human life, commonly designated as “two kingdoms” or in German zwei Reiche. The problem with that terminology is that Luther used it in at least three different ways. Sometimes it is roughly equivalent to “church” and “secular government” or, in more modern terminology, “state”: at others, it refers to the rule and domain of God and that of Satan. In this sense I have come to use “two kingdoms.” However, different from both is what is described in the hermeneutical principle of Luther’s recognition that human life takes place in a “realm” of relationship with God and in a quite distinct “realm” of relationships with God’s creatures, human and other.9
Among the many theologians before and after Augustine who accentuated God’s grace and mercy, none matched Luther in developing the anthropological implications of the nature of the Creator as sole originator of all that exists, of all that is good, for understanding that our humanity is totally a product of God’s creative and re-creative Word.
These three interpretive pillars of Luther’s theology are inseparably intertwined in all his mature writing. Without the distinction of law and gospel as God’s performative address to sinners, the twofold righteousness stands as a glimpse into our humanity without notice of its source and cause as well as of the dynamic involved in God’s rescue and restoration of sinners as his children. Without the two kinds of righteousness, concepts of law and gospel can still end up with the position that Chemnitz was rejecting—if one is seeing the gospel as the means by which we produce righteous works that are what in the final analysis do make a difference in how God views us. Luther’s insight that even in the final analysis our righteousness is the pure gift of a gracious God from beginning to end preserves the true comfort of the gospel. A failure to take seriously the two realms or dimensions of human life can let active righteousness seem to count for some merit in God’s sight in the vertical realm, before God himself. Therefore, Luther’s proclamation of the biblical message depended on all three.
For years I mushed together these three discrete tenets or presuppositions of Luther’s thinking. In 2001 my then doctoral student Makito Masaki mustered the courage to tell his advisor that I was confusing the three. He showed me that in the vertical dimension of life, God speaks the law of the first three commandments and demands not only that we fear, love, and trust in him above all things but he also requires our prayer, praise, and attention to his Word. In this dimension he also speaks the gospel that restores our righteousness. In that dimension of life we passively receive that righteousness and actively pray and praise him and devour his Word. In the horizontal dimension of life our identity and motivation are given by the gospel that identifies us in our total passivity as God’s born-again righteous children, with the complete passivity of children in the birth process, while the law prescribes the behavior and conduct that pleases the heavenly Father and actively serves his human creatures and his world.
Luther had learned much from Augustine, particularly that God’s grace alone delivers from sin. But he also parted company with his ancient forbearer in the faith because Augustine believed that God’s grace produces good works in believers that forms the basis of their worthiness in God’s sight alongside his merciful forgiveness.  Among the many theologians before and after Augustine who accentuated God’s grace and mercy, none matched Luther in developing the anthropological implications of the nature of the Creator as sole originator of all that exists, of all that is good, for understanding that our humanity is totally a product of God’s creative and re-creative Word. Thus, in Luther’s study of Scripture he came upon a foundational insight that the ancient Hebrews, with their sense of what it means that God is Creator out of nothing, had expressed. That is an insight that other cultures, with presuppositions and conceptual frameworks developed apart from that starting point, could not envision.
There is one righteous person, a person defined by God’s grace and the death and resurrection of Christ. His death and resurrection have placed the old sinful identity of the person in the Lord’s tomb and resurrected the person as a new creature, trusting and hearkening to the Lord.
Jesus taught that God’s law distinguishes two ways in which his human creatures are to be what he made them to be, what defines humanity. He did not give a single line of prescription but two. First, we are “to love the Lord your God with all your heart, and with all your soul, and with all your mind.” That commandment, he said, takes precedence. Loving God comes only through the gift of God; sinners cannot muster, make, or manage this total love and trust. Adam and Eve were created (passive voice!) with it, and we must be re-created to trust him once he has taken away our sinfulness under the condemnation of death. Then, the second commandment that defines our humanity, informs us, according to Jesus, that we are designed to love the neighbor. In Matthew 22: 34-40 he had sketched the two-sided nature of the human being’s righteousness or human identity.
Luther initially used the Latin terms “aliena” and “propria” for the two kinds of righteousness, for instance, in his 1518 pamphlet, On Threefold Righteousness,  and in the 1519 treatise On Twofold Righteousness.  The first treatise had spoken of actions that externally conformed to God’s law performed by those outside the faith in Christ alongside the righteousness of faith that is passively received and acted out in praise to God and service to others. Why he did not discuss the righteousness that outwardly conforms to God’s plan for human life apart from faith in Christ—what he later termed “civil righteousness”—in the second treatise he did not record. Perhaps his world of only baptized Christians made it unnecessary to discuss that facet of our world, in which civic righteousness is such an important concept. It is certain that he did not abandon the concept.
His designation of righteousness as “aliena”—from outside ourselves—later gave way to “iustitia passiva” as the term that makes more explicit that God alone establishes our core identity as his children, liberated from sin and all other enemies, liberated to live in trust in him. “Iustitia propria”—our own righteousness, that is the righteousness that we perform—became “iustitia activa” as the designation of the godly activities that the Holy Spirit produces as we carry out God’s commands.
The translation of “zweierlei Gerechtigkeit” as “two kinds of righteousness” makes clear that the one righteousness that defines our persons comes from God alone. In receiving it as “the real me” I am completely passive. In contrast, my active righteousness is experienced in my own behavior and the thinking and willing that goes on behind it, under the direction and with the empowerment of the Holy Spirit. The translation of the phrase as “twofold righteousness” emphasizes that there are not two parts of the child of God that can be turned on or off at different times. There is one righteous person, a person defined by God’s grace and the death and resurrection of Christ. His death and resurrection have placed the old sinful identity of the person in the Lord’s tomb and resurrected the person as a new creature, trusting and hearkening to the Lord. God’s declaration that I am righteous in his sight is met by my faith’s counter-declaration (though not “counter” in the sense of rejection but in the sense of an affirmative response of agreement). The same faith that throws itself completely on God’s love and faithfulness concludes that if God thinks that I am righteous, I want to—and do, though somewhat falteringly— practice being his righteous child. For this reason, although Luther distinguished what later Lutherans would differentiate as justification and sanctification as sharply as they did, he also saw a seamless transition in the practice of the two. My trust in the fact that God has forgiven me and through his Word made me this new creature leads naturally and willingly to the obedience that carries out the identity that the word of absolution bestows.
This is an excerpt from “The Alien and the Proper: Luther's Two-Fold Righteousness in Controversy, Ministry, and Citizenship,” edited by Robert Kolb (1517 Publishing, 2023), pgs XIII-XIX
1. Dr. Martin Luthers Werke (Weimar: Böhlau, 1883- ) [henceforth WA] 40,I:45,24-27; Luther’s Works (Saint Louis and Philadelphia: Concordia and Fortress, 1958-1986) [henceforth] LW 26:7. For a summary of Luther’s definition of “righteousness,” and bibliography, see Bengt Hägglund, “Gerechtigkeit. VI. Reformations- und Neuzeit,“ Theologische Realenzyklopädie XII (Berlin: de Gruyter, 1984): 432-434, 440. See also the December 1998 Beiheft issue of Zeitschrift für Theologie und Kirche 95, on Luther’s understanding of righteous- ness and justification, particularly as it pertains to the “Joint Declaration on the Doctrine of Justification” (which ignores Luther’s distinction of the two kinds of righteousness); see especially Reinhard Schwarz, “Luthers Rechtfertigungslehre als Eckstein der christlichen Theologie und Kirche,” Zeitschrift für Theologie und Kirche 95, Beihelf 10 (1998): 15-46.
2. LW 31: 297-306.
3. E.g.Paul Althaus, The Theology of Martin Luther, trans. Robert C. Schultz (Philadelphia: Fortress, 1966), 224-250.
4. Melanchthons Werke in Auswahl, ed. Robert Stupperich 2, 2 (Gütersloh: Bertelsmann, 1953): 372.
5. Ibid., 386.
6. E.g., in Ap IV, para. 147-151 and the discussion leading up to it, where love, as the righteousness of the fulfillment of the law, is contrasted with faith’s righteousness, Die Bekenntnisschrfiten der Evangelische-Lutherischen Kirche, ed. Irene Dingel (Göttingen: Vandenhoeck & Ruprecht, 2014), 324/325-326/327 (314/315-338/339), The Book of Concord, ed. Robert Kolb and Timothy J. Wengert (Minneapolis: Fortress, 2000), 143 (139-149).
7. Martin Chemnitz, Examen concilii Tridentini, ed. Eduard Preuss (1861; Darmstadt: Wlssenschaftliche Buchgesellschaft, 1972), 153, English translation: Examination of the council of Trent, Part I, trans. Fred Kramer (Saint Louis: Concordia, 1971), 481-482.
8. Johann Haar, Initium creaturae Dei. Eine Untersuchung über Luthers Begriff der “neuen Creatur” im Zusammenhang mit seine Verständnis von Jakobus 1,18 und mit seinem “Zeit”-Denken (Gütersloh: Bertelsmann, 1939); Robert Kolb, “Resurrection and Justification. Luther’s Use of Romans 4,25,” Lutherjahrbuch 78 (2011), 39-60.
9. Robert Kolb, “Luther’s Hermeneutics of Distinctions: Law and Gospel, Two Kinds of Righteousness, and Two Realms,” The Oxford Handbook of Martin Luther’s Theology, co-edited with Irene Dingel and Lubomir Batka (Oxford: Oxford University Press, 2014), 168-184.
10. Walter Bienert, ‘”Im Zweifel näher bei Augustin”? – Zum patristischen Hintergrund der Theologie Luthers’. In Damaskinos Papandreeou et al., eds. Oecumenica et Patristica. (Stuttgart: Kohlhammer, 1989), 179-181.
11. WA 2: 43-47.
12. WA 2:145-152 , LW 31: 297-306.