This week I am in Denver, Colorado for the national meeting of the Evangelical Theological Society where I presented a paper reviewing the past and present of historical theology while considering what it would mean to do historical theology for the church. What follows is an excerpt from the first half of that paper. The entire paper will function as an introduction to a new volume, Historical Theology for the Church, from B&H Academic, of which I am serving as co-editor with Nathan A. Finn and Thomas White.
The Lord’s Remembrancer
When David Levin set out to describe the early years of the life of Cotton Mather (1663-1703), he dubbed him “the Lord’s Remembrancer.” This title is, no doubt, taken from the oldest functioning judicial position in England, the King’s Remembrancer. Established in the twelfth century, this clerk serves the monarchy by reminding of previous business recorded. Yet, bestowing Mather with this honorific comes with some controversy given his role in the Salem witch trials. That chapter in Mather’s life often overshadows his prodigious work as historian, biographer, and biblical commentator.
Mather’s magnum opus, the Magnalia Christi Americana, is an example of his careful work and is the primary reason why Levin gives Mather the title of the Lord’s Remembrancer. Written to provide an ecclesiastical history of New England, Levin praises Mather for his faithful historical work stating that his “strength as a historian grows out of the range and number of his examples, and the persistence of his theme – the piety, the faith, the struggle, the perplexity, and the resignation in dozens of actual lives.”
Such is a fitting description of the task of the historical theologian—a servant of the church who reminds present and future readers of previous actions and theological developments from earlier eras in the history of Christianity. As the Lord’s Remembrancers, faithful historical theologians have the opportunity of serving the church present and future, but what does that entail? How is this work done? This paper will present a retrospective survey of the history of historical theologies with a view toward articulating the prospects of the pursuit of the task of crafting historical theology for the church.
What is Historical Theology?
Before examining the past or considering the future, one needs first to ask whether it is possible even to arrive at an evaluation of theology in history? C. S. Lewis, as one answering this question, remarked that most history cannot be known, and asserted that “A single second of lived time contains more than can be recorded.” Lewis was not saying nothing from history can be known for he recognized that “important parts of the past survive.” Therefore, what is recorded is worth knowing and analyzing, and from that one can discern truths about the past to the degree that comparisons to other eras can be made, and one can track the way the authors understood various doctrines in their own time and context.
If studying the past has value, and truth from the past can be ascertained to formulate a field of study called history, what then is historical theology? The next section will examine the history of historical theology, how long historians have been studying the development of theology in history, and who are the primary figures, but for now this section aims to arrive at a common definition. Essentially, historical theology is a process of historical inquiry that serves and supports other distinct but compatible disciplines. On the way to arriving at a definition of historical theology, a helpful approach is to set historical theology in relief against these other disciplines.
First, historical theology complements systematic and biblical theology by providing a historical context for classical doctrines whether they find their organization by a collection of biblical references across the Bible (systematic) or through each book and from the cannon as a facet of the story of the Bible (biblical).
Second, historical theology complements church history by providing a repository for the historical development of doctrines alongside the development of the people, places, events, and social factors that comprise the story of the history of Christianity. Church history reviews the history of the theologians while historical theology investigates the theologians’ ideas.
Alister McGrath notes that this teaching function of historical theology as a pedagogical tool is unique to the field. The study of historical theology allows Christians and churches to make sense of what they have inherited as well as to receive instruction from those who have lived in other times and who persevered through other trials. McGrath explains, “It is virtually impossible to do theology as if it had never been done before. There is always an element of looking over one’s shoulder, to see how things were done in the past, and what answers were then given. Part of the notion of ‘tradition’ is a willingness to take seriously the theological heritage of the past.”
To illustrate this function, consider what happens when a person walks up to observe two other people playing the game of Chess. The two opponents started the game some time previous and thus the onlooker is forced to survey the Chess board, make an assessment of what has happened, who is winning, whose turn is next, and who has the advantage. The onlooker observes a game in progress and, depending upon her knowledge of the game, is forced to put the pieces together in order to appreciate what is happening. The more one knows the game, the more one can adapt to this quickly, but anyone would prefer to have observed the game from the beginning to appreciate the match in full.
Second to that, the onlooker would find help if the opponents paused their game to explain to her how many moves had occurred, what mistakes had been made, and what each player was thinking at the time. A third level of intrigue and complexity could occur should one of the players leave his game and ask the onlooker to take over and play for him. At this point, for the onlooker to have a chance, she would have to have knowledge, experience, and a sense of not only what she has inherited, but also what she should do next.
Such it is with the study of historical theology. Christians of the present and future, once they start their journey in the Christian life, either as individuals or in local churches, are put in the position of the onlooker. Christians before them are playing or have played many Chess games with the Christian tradition, each developing their skills with the doctrines of the Bible as well as contributing new understanding to how the Christian life is lived in each era and under unique circumstances. The onlooker is helped if she has the opportunity not only to study and learn in community the rules of the game, that comes through the study of the Bible, but also to learn from and observe other Christians, nearby and in previous ages, how they have done the same.
Further, often in local churches or in families, the onlooker is asked to take over a game when they are brought into a church tradition, or move to a new community, or join a new Christian family. The discipleship that comes through the study of historical theology can aid the onlooker in understanding her new surroundings, what has taken place before, and how to know what should take place next. Historical theology is the pedagogical tool to aid Christians with these situations they will encounter.
In terms of formal definitions of historical theology as a discipline, this paper presents three of the most common to show a mutual understanding before concluding with an original definition.
Timothy George (1986) defined historical theology as “the study of what the church of Jesus Christ believes, teaches, and confesses on the basis of the Word of God.” 
Alister McGrath (1998) defined historical theology as “the branch of theological inquiry which aims to explore the historical development of Christian doctrines, and identify the factors which were influential in their formulation.”
Gregg Allison (2011) defined historical theology as “the study of the interpretation of Scripture and the formulation of doctrine by the church of the past.”
This section concludes with the following working definition: historical theology is the study of the development of Christian doctrine and tradition from the Bible, by the church, and for the church.
 David Levin, Cotton Mather: The Young Life of the Lord’s Remembrancer, 1663-1703 (Harvard, 1978).
 Ibid., 262.
 C. S. Lewis, “Historicism,” in Christian Reflections ([Eerdmans, 1967] Harper Collins, 2014), 132.
 Ibid., 134.
 Alister McGrath, Historical Theology (Wiley-Blackwell,  2012), 12.
 Timothy George, “Dogma Beyond Anathema: Historical Theology in the Service of the Church,” in Review & Expositor 4 (Fall 1987), 703.
 Alister McGrath, Historical Theology, 9.
 Gregg R. Allison, Historical Theology (Zondervan, 2011), 23.