Theology of Martin Luther
The theology of Martin Luther was instrumental in influencing the Protestant Reformation, specifically topics dealing with justification by faith, the relationship between the Law and Gospel (also an instrumental component of Reformed theology), and various other theological ideas. Although Luther never wrote a systematic theology or a "summa" in the style of St. Thomas Aquinas, many of his ideas were systematized in the Lutheran Confessions. Justification by faith. "This one and firm rock, which we call the doctrine of justification," insisted Luther, "is the chief article of the whole Christian doctrine, which comprehends the understanding of  all godliness." Lutherans tend to follow Luther in this matter. For the Lutheran tradition, the doctrine of salvation by grace alone through faith alone in Christ alone is the material principle upon which all other teachings rest. Luther came to understand justification as being entirely the work of God. Against the teaching of his day that the believers are made righteous through the infusion of God's grace into the soul, Luther asserted that Christians receive that righteousness entirely from outside themselves; that righteousness not only comes from Christ, it actually "is" the righteousness of Christ, and remains outside of  us but is merely imputed to us (rather than infused into us) through faith. "That is why faith alone makes someone just and fulfills the law," said Luther. "Faith is that which brings the Holy Spirit through the merits of Christ". Thus faith, for Luther, is a gift from God, and ". . .a living, bold trust in God's grace, so certain of God's favor that it would risk death a thousand times trusting in it." This faith grasps Christ's righteousness and appropriates it for itself in the believer's heart. Luther's study and research led him to  question the contemporary usage of terms such as penance and righteousness in the Roman Catholic Church. He became convinced that the church had lost sight of what he saw as several of the central truths of Christianity — the most important being the doctrine of justification by faith alone. He began to teach that salvation is a gift of God's grace through Christ received by faith alone. As a result of his lectures on the Psalms and Paul the Apostle's Epistle to the Romans, from 1513–1516, Luther "achieved an exegetical breakthrough, an insight into the all-encompassing grace of  God and all-sufficient merit of Christ." It was particularly in connection with Romans 1:17 "For therein is the righteousness of God is revealed from faith, to faith: as it is written: 'The just shall live by faith.'" Luther came to one of his most important understandings, that the "righteousness of God" was not God's active, harsh, punishing wrath demanding that a person keep God's law perfectly in order to be saved, but rather Luther came to believe that God's righteousness is something that God gives to a person as a gift, freely, through Christ. "Luther emerged  from his tremendous struggle with a firmer trust in God and love for him. The doctrine of salvation by God's grace alone, received as a gift through faith and without dependence on human merit, was the measure by which he judged the religious practices and official teachings of the church of his day and found them wanting." Luther explained justification this way in his Smalcald Articles: Law and Gospel. Another essential aspect of his theology was his emphasis on the "proper distinction" between Law and Gospel. He believed that this principle of interpretation was an essential starting point in  the study of the scriptures and that failing to distinguish properly between Law and Gospel was at the root of many fundamental theological errors. Universal priesthood of the baptized. According to some interpreters, especially Philipp Jakob Spener, Luther developed the notion of all believers being "part of one body" as a means to claim the priesthood of all believers. While the notion and meaning is somewhat unclear, this concept was clearly developed in opposition against a prevailing medieval division of Christians into "spiritual" (the hierarchy) and "temporal" Christians (the laity). In this view all Christians are "priests" in the eyes  of God. This notion is common to all Christian denominations generally labeled as "protestant". Section::::"Simul justus et peccator". Roman Catholic theology maintains that baptism washes away original sin. However, "concupiscence" remains as an inclination to sin, which is not sin unless actualized. Luther and the Reformers, following Augustine, insisted that what was called "concupiscence" was actually sin. While not denying the validity of baptism, Luther maintains that the inclination to sin is truly sin. "Simul justus et peccator" means that a Christian is at the same time both righteous and a sinner. Human beings are justified by grace alone, but  at the same time they will always remain sinners, even after baptism. The doctrine can be interpreted in two different ways. From the perspective of God, human beings are at the same time totally sinners and totally righteous in Christ (totus/totus). However, it would also be possible to argue that human beings are partly sinful and partly righteous (partim/partim). The doctrine of "simul justus" is not an excuse for lawlessness, or a license for continued sinful conduct; rather, properly understood, it comforts the person who truly wishes to be free from sin and is aware of the inner  struggle within him. Romans 7 is the key biblical passage for understanding this doctrine. Luther also does not deny that the Christian may ever "improve" in his conduct. Instead, he wishes to keep Christians from either relying upon or despairing because of their own conduct or attitude. 18th century philosopher Immanuel Kant's doctrine of radical evil has been described as an adaptation of the Lutheran "simul justus et peccator". Two Kingdoms. Martin Luther's doctrine of the two kingdoms (or two reigns) of God teaches that God is the ruler of the whole world and that he rules in  two ways, both by the law and by the gospel. God rules the earthly kingdom through secular government, by means of law and the sword. As creator, God would like to promote social justice, and this is done through the political use of the law. At the same time, God rules his spiritual kingdom in order to promote human righteousness before God. This is done through the gospel, according to which all humans are justified by God's grace alone. This distinction has in Lutheran theology often been related to the idea that there is no particular Christian contribution to  political and economic ethics. Human reason is enough to understand what is a right act in political and economic life. The gospel does not give any contribution to the content of social ethics. From this perspective Lutheran theology has often supported those in political and economic power. New Finnish School. Finnish scholarship in recent years has presented a distinctive view of Luther. Tuomo Mannermaa at the University of Helsinki led "The New Finnish Interpretation of Luther" that presents Luther's views on salvation in terms much closer to the Eastern Orthodox doctrine of theosis rather than established interpretations of German  Luther scholarship. Mannermaa's student Olli-Pekka Vainio has argued that Luther and other Lutherans in the sixteenth century (especially theologians who later wrote the Formula of Concord) continued to define justification as participation in Christ rather than simply forensic imputation. Vainio concludes that the Lutheran doctrine of justification can deny merit to human actions, "only if the new life given to the sinner is construed as participation in the divine Life in Christ. . . . The faith that has Christ as its object, and which apprehends Him and His merit, making Him present as the form of faith, is reckoned as  righteousness". The Finnish approach argues that it is due to a much later interpretation of Luther that he is popularly known as centering his doctrine of human salvation in the belief that people are saved by the imputation to them of a righteousness not their own, Christ's own ("alien") righteousness. This is known as the theological doctrine of forensic justification. Rather, the Finnish School asserts that Luther's doctrine of salvation was similar to that of Eastern Orthodoxy, theosis (divinization). The Finnish language is deliberately borrowed from the Greek Orthodox tradition, and thus it reveals the intention and context  of this theological enterprise: it is an attempt by Lutherans to find common ground with Orthodoxy, an attempt launched amid the East-West détente of the 1970s, but taking greater impetus in a post-1989 world as such dialogue appears much more urgent for churches around the Baltic. The New Finnish Interpretation has been challenged because it ignores Luther's roots and theological development in Western Christendom, and it characterizes Luther's teaching on Justification as based on Jesus Christ's righteousness which indwells the believer rather than his righteousness as imputed to the believer. Kolb and Arand (2008) argue that , "These views ignore the radically different metaphysical base of Luther's understanding and that of the Eastern church, and they ignore Luther's understanding of the dynamic, re-creative nature of God's Word." In the anthology "Union with Christ: The New Finnish Interpretation of Luther" the topic of Osiandrianism is addressed because the Finnish School is perceived as a repristination of Andreas Osiander's doctrine of salvation through Christ's indwelling the believer with his divine nature. Demonology. Luther continued a tradition of Christian engagement with the demonic from his medieval predecessors. For instance, during his Table Talks, he  references Mechthild of Magedburg's "The Flowing Light of the Godhead", an example of the pre-reformation piety which Luther was immersed in that associate the Devil with excrement. Luther references Mechtihild's work, suggesting that those in a state of mortal sin are eventually excreted by the Devil. Joseph Smith states that Luther's advice regarding the Devil, is "that one should address the devil as such" quoting: "Devil, I also shat into my pants, did you smell it, and did you record it with my others sins?’ (Tischreden 261,b) Other instances include him rehearsing medieval scatalogical limericks: < poem> Devil: You monk on the latrine, you may not read the matins here! Monk: I am cleansing my bowels and worshipping God Almighty; You deserve what descends and God what ascends."</poem> He separately states: