What is theology, and why every Christian already does it

Somebody at a bus stop says, "God will not punish anyone; he is too kind for that." A pastor on the radio says, "If you have faith, you will never be sick." A grieving mother says, "God took my child because he needed another angel." A student says, "All religions lead to the same God."

None of these people is a professor. All of them are doing theology.

That is the first thing to understand about the subject. Theology is not something only scholars in libraries do. It is what happens whenever anyone thinks about God, speaks about God, or acts on beliefs about God. The question is never whether you will have a theology. The question is whether it will be a true one.

What the word means

The word comes from two Greek words: theos, God, and logos, word or reasoning. Theology is reasoned speech about God — the attempt to think and speak truly about who God is, what he has done, and what that means for us.

The most famous definition comes from Anselm, an eleventh-century monk who later became Archbishop of Canterbury. He described theology as fides quaerens intellectum — "faith seeking understanding". The order matters. Anselm did not say you must understand everything before you can believe. He said that people who already trust God naturally want to understand the God they trust. In his own words, he did not seek to understand in order to believe; he believed in order to understand.

That is a healthy place to start. A child trusts her father long before she can explain him, and as she grows she wants to know him better. Theology is that growing.

Everyone already has a theology

Go back to the bus stop. Each of those statements contains a belief about God's character, about suffering, about salvation, about what happens after death. Some of them are partly right. Some are badly wrong. But every one of them is a theology.

C. S. Lewis made this point in Mere Christianity with an illustration about maps. He compared theology to a map of the sea. A map is not the same as the sea itself — walking on the beach is more vivid than looking at paper. But if you actually want to get somewhere, the map, drawn from the experience of thousands of travellers, is far more useful than your own impression of a few waves. People who say they do not want doctrine, only a feeling of God, usually end up, Lewis warned, with crude and out-of-date ideas rather than none at all.

That warning matters in our setting. Many Christians across Africa have absorbed theology from songs, from popular preachers and from the beliefs around them rather than from careful reading of Scripture. Some of it is sound. Some of it is a mixture — the gospel blended with ideas about curses, fate or wealth that come from elsewhere. Byang Kato, the Nigerian theologian who led the Association of Evangelicals of Africa in the 1970s, warned in Theological Pitfalls in Africa that the church on the continent was growing faster than its understanding. He was not against African theology; he was for theology that was African in expression and biblical in substance.

The branches of theology

Theology is a large field, and it helps to know how it is usually divided. There are four main branches.

These are not rival approaches. They are four angles on the same task. Biblical theology keeps us faithful to the story and to each author's voice. Systematic theology keeps us from contradicting ourselves. Historical theology keeps us humble — most of our questions have been asked before, often by wiser people. Practical theology keeps us honest: doctrine that changes nothing has not really been understood.

What the -ologies mean

Systematic theology divides its subject into topics, and each has a name that can sound intimidating. They are just labels. Here are the ones you will meet throughout the Harvest Theology Academy:

• Theology proper — the doctrine of God himself: his nature and attributes, and the Trinity.
• Bibliology — the doctrine of Scripture: inspiration, authority, canon.
• Anthropology — the doctrine of humanity: what it means to be made in God's image.
• Hamartiology — the doctrine of sin (from hamartia, missing the mark).
• Christology — the doctrine of Christ: who Jesus is, fully God and fully man.
• Pneumatology — the doctrine of the Holy Spirit (from pneuma, breath or spirit).
• Soteriology — the doctrine of salvation (from sōtēria, rescue or deliverance): grace, faith, justification, sanctification.
• Ecclesiology — the doctrine of the church (from ekklesia, assembly).
• Eschatology — the doctrine of the last things (from eschatos, last): the return of Christ, resurrection, judgement and the new creation.

Notice that they connect. You cannot get your christology right and your soteriology wrong for long, because what Jesus did depends on who he is. A mistake in one place eventually shows up everywhere else, which is why the parts are studied together.

Where theology comes from: the sources

How do we know anything about God at all? Christians have generally recognised four sources, though they weigh them differently.

Scripture

The Bible is God's own word. "All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness" (2 Timothy 3:16). For evangelical Christians it is the supreme and final authority — the Reformation principle of sola Scriptura. That does not mean Scripture is the only thing we ever consult; it means that everything else is tested by it, and Scripture is tested by nothing above it.

Tradition

Tradition is the accumulated understanding of the church — the creeds, the confessions, the great teachers. Roman Catholic and Orthodox Christians give tradition, rightly interpreted by the church, an authority alongside Scripture. Protestants treat it as a trusted but fallible guide. Either way, ignoring it is foolish. The Nicene Creed is not Scripture, but anyone who reads the Bible and concludes that Jesus is a created being has gone wrong somewhere, and the creed helps them see where.

Reason

God made us able to think. Reason helps us read texts carefully, notice contradictions, follow arguments and apply truth to new situations. But reason is a tool, not a judge. Our thinking is affected by sin and limited by being creatures. When reason sets itself above revelation — "I will only believe what I can fully explain" — it has overstepped.

Experience

Christians genuinely experience God: answered prayer, conviction of sin, the comfort of the Spirit. Experience matters, and Pentecostal and charismatic Christians have rightly reminded the wider church of this. But experience must be interpreted, and it can mislead. A powerful feeling at a crusade is not, by itself, proof that what was preached was true. Scripture tells us to "test the spirits" (1 John 4:1).

Theology is meant to end in worship

Read Romans 9–11. It is some of the hardest theological argument in the Bible — about Israel, election, mercy and the purposes of God across history. And how does Paul finish it?

Oh, the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgements and how inscrutable his ways!— Romans 11:33

The argument ends in a song. That is what good theology does. It does not leave you feeling clever; it leaves you amazed. An old Christian saying puts it this way: lex orandi, lex credendi — the way we pray shapes what we believe, and what we believe shapes how we pray. Theology and worship belong together.

It also ends in obedience. Paul prays that the Colossians would be "filled with the knowledge of his will in all spiritual wisdom and understanding, so as to walk in a manner worthy of the Lord" (Colossians 1:9-10). Knowledge leads to walking. Doctrine that does not change how you treat your wife, your employees or your enemies has been memorised, not learned.

The danger of pride, and the need for humility

There is a real risk in studying theology, and the Bible names it. "Knowledge puffs up, but love builds up. If anyone imagines that he knows something, he does not yet know as he ought to know. But if anyone loves God, he is known by God" (1 Corinthians 8:1-3).

Every Bible college has students who learn enough Greek to correct their pastor and not enough grace to do it kindly. Theology can become a way of winning arguments, of feeling superior to "ordinary" believers, or of keeping God at arm's length by turning him into a subject.

Three habits guard against this.

1. Remember what is hidden. "The secret things belong to the LORD our God, but the things that are revealed belong to us and to our children for ever, that we may do all the words of this law" (Deuteronomy 29:29). Some things God has not told us. Good theologians know where to stop.
2. Study on your knees. Begin and end study with prayer. Ask God not only to inform you but to change you.
3. Stay in the church. Theology done alone tends towards eccentricity. Done in a congregation, among people who will love you and correct you, it stays healthy.

Why it matters to you

You will be asked questions. Your children will ask why God allows suffering. A Muslim colleague will ask how God can have a Son. A cousin who has joined a new movement will tell you Jesus was not really God. A friend will ask whether her late father, who never went to church, is with God. The Bible says, "Always being prepared to make a defence to anyone who asks you for a reason for the hope that is in you; yet do it with gentleness and respect" (1 Peter 3:15).

Theology is how you get ready. Not so that you can win, but so that when someone you love is confused or grieving, you have something true to give them.

The rest of the Theology Academy takes the major doctrines one at a time. You do not need to master them all at once. Begin where you are, with the Bible open, praying, and in the company of other believers. That is how every faithful theologian in history began.