Biblical and systematic theology

One Bible, two ways of gathering

The Bible is sixty-six books, written by many authors in many forms over well over a thousand years. So how do we learn what the whole of it teaches about God, or sin, or salvation? Theology has answered in two main ways. One gathers the Bible's teaching by subject. The other follows the Bible's own story from beginning to end.

Both start in the same place: reading a passage carefully and asking what it says where it stands. This is exegesis. When the exiles had come home from Babylon, Ezra and the Levites read God's law to the assembled people: "they read from the Book of the Law of God, explaining it and giving insight, so that the people could understand what was being read" (Nehemiah 8:8). Reading, explaining and understanding: that is the root of both kinds of theology (see Interpreting Scripture).

By subject: systematic theology

Systematic theology collects what all of Scripture says on one subject and sets it out in order. What is God like? What is a human being? Who is Christ and what has he done? For each question it listens to the whole Bible, Genesis to Revelation, and asks how the answers fit together. Older theologians called these subjects loci, ‘places’ or ‘headings’.

The method is old. In the 1150s Peter Lombard, a teacher of theology in Paris, arranged sayings of Scripture and the Fathers, Augustine above all, under headings in four books of Sentences: God and the Trinity; creation and sin; the incarnation and the virtues; the sacraments and the last things. It became the theology textbook of the medieval universities for centuries. Thomas Aquinas lectured on it, and so did the young Martin Luther Peter Lombard, Sentences.

The Reformation gave the method a new shape. In 1521 Philip Melanchthon, Wittenberg's young professor of Greek, published his Loci Communes, arranged by the subjects he had met in lecturing on Romans: sin, law, grace, faith, justification. It is often called the first Protestant systematic theology Melanchthon, Loci Communes. In it he argued that to know Christ is not to speculate about his natures but to know the benefits he gives. Systematic theology, on this view, is for comfort and life, not only for the head.

John Calvin's Institutes of the Christian Religion first appeared in 1536 as a small book and grew through edition after edition. The final Latin edition of 1559 follows, broadly, the shape of the Apostles' Creed: God the Creator, God the Redeemer in Christ, the Spirit's work by which we receive Christ's grace, and the church and sacraments Calvin, Institutes. The creeds themselves move this way, from God and creation to Christ, the Spirit, the church and the life to come. This app's doctrine course follows the same order, from God makes himself known to the new creation.

Paul reminded the Ephesian elders, "I did not shrink back from declaring to you the whole will of God" (Acts 20:27). Matthew Henry, using the older wording, comments: "He had preached to them the whole counsel of God. As he had preached to them the gospel purely, so he had preached it to them entire" Matthew Henry. That is the goal of systematic theology: not a few favourite verses, but all that Scripture says, heard together. It has its own danger, though. Verses lifted out of their setting and pressed into a frame built in advance can let the system rule the Bible instead of the Bible ruling the system.

By story: biblical theology

The Bible was not written as a dictionary of topics. It is a story: creation and fall, Abraham and the exodus, David and the exile, Christ and his church, a new heaven and a new earth. Along the way God makes himself known more and more clearly.

On many past occasions and in many different ways, God spoke to our fathers through the prophets. But in these last days He has spoken to us by His Son, whom He appointed heir of all things, and through whom He made the universe.

Hebrews 1:1-2

On this passage Henry writes, "We never can be thankful enough that God has in so many ways, and with such increasing clearness, spoken to us fallen sinners concerning salvation" Matthew Henry. Biblical theology follows that increasing clearness. The risen Jesus did it on the road to Emmaus: "beginning with Moses and all the Prophets, He explained to them what was written in all the Scriptures about Himself" (Luke 24:27). Biblical theology hears what each book and each age said in its own time, and traces how that word grows, covenant by covenant, until it reaches Christ.

The name as a separate discipline is usually traced to Johann Philipp Gabler. In his inaugural address at the University of Altdorf in 1787 he proposed distinguishing biblical theology, a historical task describing what the biblical writers taught in their own times, from dogmatic theology, in which theologians set out the faith for their own day Gabler, On the Proper Distinction between Biblical and Dogmatic Theology. He wanted dogmatics to rest on a firm biblical foundation rather than on the systems of the schools. In the century that followed, though, many scholars treated biblical theology as history cut loose from faith, and some heard in the Bible only voices that did not agree.

In 1894 Geerhardus Vos, giving his inaugural address at Princeton Theological Seminary, defined biblical theology as the study of the history of special revelation: how God's self-disclosure unfolded in history Vos, The Idea of Biblical Theology. For Vos revelation is not a collection of competing ideas but the word of one God, given more fully at each stage of the history of redemption. He liked to describe that growth as organic, like a seed becoming a tree, and his approach has shaped many evangelical scholars since.

Evangelicals do not all draw the Bible's large shape the same way. Covenant theology, dispensationalism and new covenant theology explain differently how the covenants relate, and how Israel and the church relate (see the doctrine course's lesson Law and covenant). The Reformed understanding is set out in the Reformed Faith course's lesson One covenant of grace in many ages.

Two ways that need each other

Each way keeps the other honest. Biblical theology keeps systematics close to the text and its story. Systematics keeps biblical theology from stopping at the separate voices, and asks how the whole of Scripture holds together. What binds them is the conviction that one God has given one Bible.

Take one theme and follow it both ways: God dwelling with his people. After the exodus God commanded, "they are to make a sanctuary for Me, so that I may dwell among them" (Exodus 25:8). Then the Son came: "The Word became flesh and made His dwelling among us" (John 1:14). The verb John uses, skēnoō (σκηνόω), means to pitch a tent, and it recalls the tabernacle in the wilderness. Paul asks the church, "Do you not know that you yourselves are God’s temple, and that God’s Spirit dwells in you?" (1 Corinthians 3:16). And John sees the end:

Behold, the dwelling place of God is with man, and He will dwell with them. They will be His people, and God Himself will be with them as their God.

Revelation 21:3

Biblical theology traces this as one line, from tabernacle to temple, through Christ and the church, to the new creation. Systematic theology gathers the same texts under its headings and asks how they fit: how the God of whom Solomon prayed, "The heavens, even the highest heavens, cannot contain You" (1 Kings 8:27), became incarnate (The incarnation), dwells by his Spirit in believers (New birth and the indwelling Spirit), and will live with his people in a new heaven and earth (Resurrection, judgment and the new creation).

Either way, the end is the same: to know and worship the one God of the whole Bible more truly. Try both in your own reading: read one book straight through as a story, and gather one subject from many books.

Practice