Introduction to Systematic Theology
What is systematic theology? Why should Christians study it? How should we study it?
EXPLANATION AND SCRIPTURAL BASIS
A. Definition of Systematic Theology
What is systematic theology? Many different definitions have been given, but for the purposes of this book the following definition will be used: Systematic theology is any study that answers the question, "What does the whole Bible teach us today?" about any given topic.
This definition indicates that systematic theology involves collecting and understanding all the relevant passages in the Bible on various topics and then summarizing their teachings clearly so that we know what to believe about each topic.
1. Relationship to Other Disciplines. The emphasis of this book will not therefore be on historical theology (a historical study of how Christians in different periods have understood various theological topics) or philosophical theology (studying theological topics largely without use of the Bible, but using the tools and methods of philosophical reasoning and what can be known about God from observing the universe) or apologetics (providing a defense of the truthfulness of the Christian faith for the purpose of convincing unbelievers). These three subjects, which are worthwhile subjects for Christians to pursue, are sometimes also included in a broader definition of the term systematic theology. In fact, some consideration of historical, philosophical, and apologetic matters will be found at points throughout this book. This is because historical study informs us of the insights gained and the mistakes made by others previously in understanding Scripture; philosophical study helps us understand right and wrong thought forms common in our culture and others; and apologetic study helps us bring the teachings of Scripture to bear on the objections raised by unbelievers. But these areas of study are not the focus of this volume, which rather interacts directly with the biblical text in order to understand what the Bible itself says to us about various theological subjects.
If someone prefers to use the term systematic theology in the broader sense just mentioned instead of the narrow sense which has been defined above, it will not make much difference. Those who use the narrower definition will agree that these other areas of study definitely contribute in a positive way to our understanding of systematic theology, and those who use the broader definition will certainly agree that historical theology, philosophical theology, and apologetics can be distinguished from the process of collecting and synthesizing all the relevant Scripture passages for various topics. Moreover, even though historical and philosophical studies do contribute to our understanding of theological questions, only Scripture has the final authority to define what we are to believe, and it is therefore appropriate to spend some time focusing on the process of analyzing the teaching of Scripture itself.
Systematic theology, as we have defined it, also differs from Old Testament theology, New Testament theology, and biblical theology. These three disciplines organize their topics historically and in the order the topics are presented in the Bible. Therefore, in Old Testament theology, one might ask, "What does Deuteronomy teach about prayer?" or "What do the Psalms teach about prayer?" or "What does Isaiah teach about prayer?" or even, "What does the whole Old Testament teach about prayer and how is that teaching developed over the history of the Old Testament?" In New Testament theology one might ask, "What does John's gospel teach about prayer?" or "What does Paul teach about prayer?" or even "What does the New Testament teach about prayer and what is the historical development of that teaching as it progresses through the New Testament?"
"Biblical theology" has a technical meaning in theological studies. It is the larger category that contains both Old Testament theology and New Testament theology as we have defined them above. Biblical theology gives special attention to the teachings of individual authors and sections of Scripture, and to the place of each teaching in the historical development of Scripture. So one might ask, "What is the historical development of the teaching about prayer as it is seen throughout the history of the Old Testament and then of the New Testament?" Of course, this question comes very close to the question, "What does the whole Bible teach us today about prayer?" (which would be systematic theology by our definition). It then becomes evident that the boundary lines between these various disciplines often overlap at the edges, and parts of one study blend into the next. Yet there is still a difference, for biblical theology traces the historical development of a doctrine and the way in which one's place at some point in that historical development affects one's understanding and application of that particular doctrine. Biblical theology also focuses on the understanding of each doctrine that the biblical authors and their original hearers or readers possessed.
Systematic theology, on the other hand, makes use of the material of biblical theology and often builds on the results of biblical theology. At some points, especially where great detail and care is needed in the development of a doctrine, systematic theology will even use a biblical-theological method, analyzing the development of each doctrine through the historical development of Scripture. But the focus of systematic theology remains different: its focus is on the collection and then the summary of the teaching of all the biblical passages on a particular subject. Thus systematic theology asks, for example, "What does the whole Bible teach us today about prayer?" It attempts to summarize the teaching of Scripture in a brief, understandable, and very carefully formulated statement.
2. Application to Life. Furthermore, systematic theology focuses on summarizing each doctrine as it should be understood by present-day Christians. This will sometimes involve the use of terms and even concepts that were not themselves used by any individual biblical author, but that are the proper result of combining the teachings of two or more biblical authors on a particular subject. The terms Trinity, incarnation, and deity of Christ, for example, are not found in the Bible, but they usefully summarize biblical concepts.
Defining systematic theology to include "what the whole Bible teaches us today" implies that application to life is a necessary part of the proper pursuit of systematic theology. Thus a doctrine under consideration is seen in terms of its practical value for living the Christian life. Nowhere in Scripture do we find doctrine studied for its own sake or in isolation from life. The biblical writers consistently apply their teaching to life. Therefore, any Christian reading this book should find his or her Christian life enriched and deepened during this study; indeed, if personal spiritual growth does not occur, then the book has not been written properly by the author or the material has not been rightly studied by the reader.
3. Systematic Theology and Disorganized Theology. If we use this definition of systematic theology, it will be seen that most Christians actually do systematic theology (or at least make systematic-theological statements) many times a week. For example: "The Bible says that everyone who believes in Jesus Christ will be saved." "The Bible says that Jesus Christ is the only way to God." "The Bible says that Jesus is coming again." These are all summaries of what Scripture says and, as such, they are systematic-theological statements. In fact, every time a Christian says something about what the whole Bible says, he or she is in a sense doing "systematic theology"-according to our definition-by thinking about various topics and answering the question, "What does the whole Bible teach us today?"
How then does this book differ from the "systematic theology" that most Christians do? First, it treats biblical topics in a carefully organized way to guarantee that all important topics will receive thorough consideration. This organization also provides one sort of check against inaccurate analysis of individual topics, for it means that all other doctrines that are treated can be compared with each topic for consistency in methodology and absence of contradictions in the relationships between the doctrines. This also helps to ensure balanced consideration of complementary doctrines: Christ's deity and humanity are studied together, for example, as are God's sovereignty and man's responsibility, so that wrong conclusions will not be drawn from an imbalanced emphasis on only one aspect of the full biblical presentation.
In fact, the adjective systematic in systematic theology should be understood to mean something like "carefully organized by topics," with the understanding that the topics studied will be seen to fit together in a consistent way, and will include all the major doctrinal topics of the Bible. Thus "systematic" should be thought of as the opposite of "randomly arranged" or "disorganized." In systematic theology topics are treated in an orderly or "systematic" way.
A second difference between this book and the way most Christians do systematic theology is that it treats topics in much more detail than most Christians do. For example, an ordinary Christian as a result of regular reading of the Bible may make the theological statement, "The Bible says that everyone who believes in Jesus Christ will be saved." That is a perfectly true summary of a major biblical teaching. However, in this book we devote several pages to elaborating more precisely what it means to "believe in Jesus Christ," and twelve chapters (chapters 32-43) will be devoted to explaining what it means to "be saved" in all of the many implications of that term.
Third, a formal study of systematic theology will make it possible to formulate summaries of biblical teachings with much more accuracy than Christians would normally arrive at without such a study. In systematic theology, summaries of biblical teachings must be worded precisely to guard against misunderstandings and to exclude false teachings.
Fourth, a good theological analysis must find and treat fairly all the relevant Bible passages for each particular topic, not just some or a few of the relevant passages. This often means that it must depend on the results of careful exegesis (or interpretation) of Scripture generally agreed upon by evangelical interpreters or, where there are significant differences of interpretation, systematic theology will include detailed exegesis at certain points.
Because of the large number of topics covered in a study of systematic theology and because of the great detail with which these topics are analyzed, it is inevitable that someone studying a systematic theology text or taking a course in systematic theology for the first time will have many of his or her own personal beliefs challenged or modified, refined or enriched. It is of utmost importance therefore that each person beginning such a course firmly resolve in his or her own mind to abandon as false any idea which is found to be clearly contradicted by the teaching of Scripture. But it is also very important for each person to resolve not to believe any individual doctrine simply because this textbook or some other textbook or teacher says that it is true, unless this book or the instructor in a course can convince the student from the text of Scripture itself. It is Scripture alone, not "conservative evangelical tradition" or any other human authority, that must function as the normative authority for the definition of what we should believe.
4. What Are Doctrines? In this book, the word doctrine will be understood in the following way: A doctrine is what the whole Bible teaches us today about some particular topic. This definition is directly related to our earlier definition of systematic theology, since it shows that a "doctrine" is simply the result of the process of doing systematic theology with regard to one particular topic. Understood in this way, doctrines can be very broad or very narrow. We can speak of "the doctrine of God" as a major doctrinal category, including a summary of all that the Bible teaches us today about God. Such a doctrine would be exceptionally large. On the other hand, we may also speak more narrowly of the doctrine of God's eternity, or the doctrine of the Trinity, or the doctrine of God's justice.
The book is divided into seven major sections according to seven major "doctrines" or areas of study:
Part 1: The Doctrine of the Word of God Part 2: The Doctrine of God Part 3: The Doctrine of Man Part 4: The Doctrines of Christ and the Holy Spirit Part 5: The Doctrine of the Application of Redemption Part 6: The Doctrine of the Church Part 7: The Doctrine of the Future
Within each of these major doctrinal categories many more specific teachings have been selected as appropriate for inclusion. Generally these meet at least one of the following three criteria: (1) they are doctrines that are most emphasized in Scripture; (2) they are doctrines that have been most significant throughout the history of the church and have been important for all Christians at all times; (3) they are doctrines that have become important for Christians in the present situation in the history of the church (even though some of these doctrines may not have been of such great interest earlier in church history). Some examples of doctrines in the third category would be the doctrine of the inerrancy of Scripture, the doctrine of baptism in the Holy Spirit, the doctrine of Satan and demons with particular reference to spiritual warfare, the doctrine of spiritual gifts in the New Testament age, and the doctrine of the creation of man as male and female in relation to the understanding of roles appropriate to men and women today. Because of their relevance to the contemporary situation, doctrines such as these have received more emphasis in the present volume than in most traditional textbooks of systematic theology.