Luther, like Augustine and Calvin, received the traditional substance of doctrine of the Trinity from the Early Church Councils while reserving the right to criticize some of the traditional philosophical terminology used to formulate the doctrine. Luther only infrequently discusses the subject of the Trinity as a distinct topic or doctrine. Consequently we have no systematic presentation of the doctrine of the Trinity by Luther himself as we have, for example, in Melanchthon’s later editions of the Loci and or in Calvin’s Institutes.
Nevertheless, Luther unambiguously embraces the orthodox Trinitarian doctrine of the church. Luther’s Christmas sermon of 1514, provides us with an early reference to Luther’s commitment to classic Trinitarianism. At this stage in Luther’s development we find him following Augustine’s lead by introducing various analogies as aids for understanding the problem of the Trinity. Luther, however, begins to break with long-standing scholastic categories in that his analogies are not restricted to the realm of human psychology. Prenter interprets:
In scholasticism the doctrine of the Trinity and anthropology are united in a manner that makes the inner essence of the human soul a reflection of the essence of God. Already in the sermon of 1514, we notice that Luther is beginning to deviate from this view, which also was very contrary to his concept of sin which held that the inner soul was touched by the fall. And when the concept motis, which also later plays a part in Luther’s presentation of the doctrine of the Trinity gets into the foreground, it seems to prove that the Trinity doctrine is no longer oriented on the basis of God’s passive nature as reflected in man’s process of understanding, but on the basis of God’s activity in revelation as it is seen in the history of revelation (Regin Prenter, Spiritus Creator, trans. John Jensen [Philadelphia: Mulenberg Press, 1953], 175).Prenter’s comments are plausible. Luther does seem to be moving beyond traditional scholastic categories. Even so, he still has a long way to travel before he arrives at formulations that eschew the language of philosophy and metaphysics. One might indeed wonder whether Luther’s Aristotelian analogies are truly proleptic or whether we are only too willing to allow our own active imaginations anachronistically to read into Luther’s earlier works vestigia of his later insights. One thing is clear. Luther’s doctrine of the Trinity is at this point only very loosely related to God’s revelation of his fullness in salvation history. The same kind of analysis might be made of Luther’s doctrine of the Trinity in the his early lectures on Romans (1515-16), Galatians (1519), and his Dictata super Psalterium (1513-1515). Although Luther sometimes uses language that might imply a creatively dynamic way of speaking about the Trinity in relationship to man, his Trinitarianism remains largely bound to traditional categories of analogy and ontology.
Of course, we do find Luther faithfully confessing the doctrine of the Trinity whenever he has the opportunity to craft a confession of faith. As Lohse puts it: “Whenever Luther formulated confessions or articles of faith, he regularly began with the doctrine of God in its Trinitarian form. For this reason it would seem appropriate to give the doctrine of God the central position in Luther’s theology." Lohse may be correct about the “centrality” of Luther’s doctrine of the Trinity, but such an assertion will certainly not be established merely by noting that Luther always “began” his confessions with an article on the Trinity. Just about everyone’s confession—Roman Catholic, Reformed, and Lutheran—contained an article on the Trinity somewhere near the top. What does this prove? Can one really establish doctrinal primacy or centrality in this way? Whether the doctrine of the Trinity is “central” in Luther’s pre-catechetical writings can be established only by examining how Luther utilizes the Trinity when it really counts. Placing an article on the Trinity at the head of one’s confession evidences Luther’s faithfulness to received doctrine, nothing more.
The evidence indicates that sometime during the years 1520-23, Luther began to articulate the reciprocal, dynamic relationship between what we now call the “economic” and “ontological” Trinity with increasing clarity and profundity. It is evident already in his A Short Form of the Faith (1520). [I don't have an English translation of this work in front of me, only the German. I've been away from my German for a while, but I'll see if I can translate it on the fly.] In this little work Luther is concerned not just with the proper formulas and terminology describing the Trinity. When he is explaining the Creed we begin to see evidence of Luther’s desire to wring out of the doctrine all of its soteriological significance for the believer. Luther may have shared certain dogmatical Trinitarian formulations with his opponents, but they are now beginning to function for Luther in a way that they did not for the Late Medieval church. Evidence of this occurs only when Luther begins to explain the Second Article. After quoting the Creed, Luther explains:
I believe that Jesus alone is truly the one Son of God, in one divine nature and essence as the eternally begotten, but also that with the Father he created all things, and with my humanity is Lord over all. .The “but also” might give the impression that the two parts of this confession concerning Jesus Christ—Christ in se and Christ pro me— are only very loosely connected. Luther does not explicitly explain the relationship between these two dimensions of Christology. Later, as we shall see, he drops the “but also” language altogether and unites what Christ “is” and what Christ “does” in the strongest possible way. Here Luther is struggling to mine these ontological statements ("divine nature and essence") for their significance pro me. This same language and order occurs in Luther’s explanation of the Third Article. One can perceive here the seeds of what will shortly blossom into a profound doctrine of the Father, Son, and Holy Spirit’s unified work of salvation pro me. Luther is not satisfied with explicating ontological relations between the Persons. This is not the real meaning of the Trinity.
Lohse makes a suggestive comment in reference to Luther’s statement on the Trinity in the Smalcald Articles that may help explain the substance and function of the "but also" clauses in this early work. At the conclusion of Part I of the Smalcald Articles (treating “the sublime articles of the divine majesty”) Luther notes: “These articles are not matters of dispute or contention, for both parties *believe and* confess them. Therefore, it is not necessary to treat them at greater length.” After noting that the words “believe and” were crossed out by Luther and not included in the official printed texts of the Articles, Lohse explains, “Naturally, Luther did not intend to imply that the dogma of the Trinity was not firmly maintained in the Roman Church. For Luther, however, faith in the triune God simultaneously required a specific doctrine of the human person and a specific doctrine of salvation; that is, faith in the triune God required the Reformation doctrine of justification. For Luther, simply accepting dogmas as true was not enough.”
Luther, then, not only affirms that the each of the Articles of the Apostle’s Creed are true, he not only assents to the received doctrinal explanations of the Father, Son, and Holy Spirit, he believes they bear significantly upon the meaning of the Christian’s relationship with God. The ontological relations are only significant because they can only be known and confessed insofar as the Holy Spirit brings us to the Father through Christ. In 1520, these ideas were in the process of germinating. When Luther returns eight years later to the Creed and its exposition he is prepared to communicate the biblical Trinitarian Gospel to “simple” Christians in his catechetical writing and preaching.
Go to Part II.