Faith and Reason

There is a popular definition of faith that Christians and their critics often share. Faith, on this view, is believing something without evidence, or even against it. The critic thinks this is a vice; some believers think it is a virtue. If the definition were right, apologetics would be either pointless or faintly disloyal, because giving reasons for faith would be like giving reasons for not needing reasons. So before anything else, it is worth asking what the Bible means by the word.

Hebrews 11:1 is the nearest thing the New Testament has to a definition. 'Now faith is the assurance of what we hope for and the certainty of what we do not see.' The King James Version, which is in the public domain, renders it: 'Now faith is the substance of things hoped for, the evidence of things not seen.' The two key nouns explain why translations differ. The first is hypostasis, literally something that stands under: a foundation, a reality, a confident standing. Hebrews uses it in 1:3, where the Son is the exact representation of God's nature, and in 3:14, where believers hold firmly to the assurance they had at first. Some scholars, drawing on its use in business papyri, have suggested something like a title deed, a document that gives present possession of a property not yet occupied, though that reading is debated. The second noun is elenchos, a proof or conviction, the result of examining and testing. Neither word describes a leap in the dark. Faith in this verse gives present reality to what is hoped for and a settled conviction about what is unseen.

Notice what the contrast is. Faith is about what we hope for and what we do not see. It is set against sight, not against reasons. Paul draws the same line: 'For we walk by faith, not by sight' (2 Corinthians 5:7). And the chapter that follows shows what faith does. Noah, warned about things not yet seen, built an ark. Abraham went out without knowing where he was going (11:8), but he knew who had called him. Sarah 'considered Him faithful who had promised' (11:11), which is a judgment about a person's character. And when Abraham was told to offer Isaac, the son through whom the promise was to come, Hebrews says that 'Abraham reasoned that God could raise the dead' (11:19). Faith in Hebrews 11 is trust in God's word and character, acting on what he has said before seeing it fulfilled, and it is not afraid to reason.

The Greek word pistis carries both sides of a relationship of trust. In Romans 3:3 it is God's own faithfulness: 'Will their lack of faith nullify God's faithfulness?' In Galatians 5:22 the BSB translates it as faithfulness, a fruit of the Spirit. To have faith in someone is to rely on them; to be faithful is to be someone who can be relied on. Biblical faith is therefore personal before it is propositional. It is not mainly believing that certain statements are true, though it includes that. It is entrusting yourself to the God who has spoken.

Protestant theologians of the sixteenth and seventeenth centuries used three Latin words to describe the parts of saving faith, and the distinction is still useful. Notitia is knowledge: you must know something of what God has said and done. Assensus is assent: you must judge it true. Fiducia is trust: you must rely on it, and on him, for yourself. James warns that assent alone is not enough: 'Even the demons believe that' God is one, he says, and they shudder (James 2:19). But trust without any knowledge or assent is not biblical faith either. You cannot rely on a God of whom you know nothing, or on a promise you judge false. This is where apologetics finds its place. It does not create trust. It can serve knowledge and assent, and it can remove obstacles that stop a person from trusting.

Fideism, from the Latin fides, faith, is the name given to views that say faith does not need, and should not seek, support from reason. Almost nobody accepts the label for himself, and the people usually given it held more careful views than the label suggests. But there is a real position here, held by serious Christians, and it deserves to be stated as its best defenders would put it.

Its most quoted ancestor is Tertullian of Carthage, whom you met in the first lesson. In his Prescription Against Heretics, written around 200, he asked what Athens has to do with Jerusalem, what the Academy has to do with the church, and he blamed the heretics of his day on philosophy. In another work, On the Flesh of Christ, he wrote of the death and resurrection of the Son of God that it is credible because it is foolish, and certain because it is impossible. (The famous phrase I believe because it is absurd, often attributed to him, is not in his writings.) Tertullian was not against thinking; he was a trained rhetorician who argued constantly. His target was the attempt to make the gospel fit what philosophers already found reasonable, and his worry was that the gospel would be trimmed to fit.

The strongest modern statement belongs to the Danish writer Søren Kierkegaard. In his Concluding Unscientific Postscript (1846), written under the pseudonym Johannes Climacus, he argued that historical inquiry can only ever give approximation, more or less probable results, and that an eternal happiness cannot be built on an approximation. Faith, he said, is not a conclusion that grows more secure as the evidence piles up. It is a passionate commitment of the whole person to the paradox that the eternal God has entered time as a man, and it is precisely the risk involved that makes it faith. His real target was Danish Christendom, where everyone was born a Christian, baptised, confirmed and buried by the state church, and where faith had become a matter of being a respectable citizen. Kierkegaard thought that a Christianity made comfortable by argument was the same disease in another form.

In the twentieth century the Swiss theologian Karl Barth gave the position its most urgent form. In 1934 his fellow Swiss theologian Emil Brunner published a short book called Nature and Grace, arguing that a point of contact for the gospel remains in fallen human nature. Barth replied with a pamphlet whose title was a single word, Nein!, No! The context matters. In Germany, the so-called German Christians were claiming that God revealed himself in the history and blood of the German people, and so in Hitler's movement, as well as in Christ. Natural theology, for Barth, was not an abstract mistake; it was the door through which an idol had walked into the church. That same year the Barmen Declaration, which he largely drafted, confessed Jesus Christ as attested in scripture as the one Word of God that the church must hear, trust and obey, and rejected any other source of revelation alongside him.

The texts fideists rely on are real. 'For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God' (1 Corinthians 1:18). 'Has not God made foolish the wisdom of the world?' (1:20). 'For since in the wisdom of God the world through its wisdom did not know Him, God was pleased through the foolishness of what was preached to save those who believe' (1:21). Paul did not come 'with persuasive words of wisdom', so that their faith 'would not rest on men's wisdom, but on God's power' (2:4-5). Jesus blesses 'those who have not seen and yet have believed' (John 20:29) and praises the Father for hiding these things 'from the wise and learned' (Matthew 11:25). From these the fideist draws three concerns that every apologist should share. A faith resting on an argument is only as strong as the argument, and arguments are refuted. A faith that needs a philosopher's approval puts philosophers in charge of the church. And a faith that requires education to be rational has abandoned the poor, who are most of the church.

The French mathematician Blaise Pascal is sometimes listed here because of a line in his Pensées, published in 1670, eight years after his death: 'The heart has its reasons, which reason does not know.' He also wrote, 'It is the heart which experiences God, and not the reason.' But Pascal spent his last years collecting arguments for a defence of Christianity, including his famous wager, so he belongs only to the gentler edge of this view: reason has limits, and the knowledge of God is not reached by reason alone. Many believers in the global south hold something like his view without ever having heard of him. Do not argue, they say; pray. They are not wrong that prayer comes first. The question is whether it comes alone.

At the other end stands rationalism, used here in the broad sense of the view that faith must wait on reason: that a person should believe the Christian faith only to the degree that he can show, by argument and evidence available to anyone, that it is true. This too has serious Christian defenders, and their concern is as pastoral as the fideist's.

The English philosopher John Locke, a lifelong Christian, wrote in his Essay Concerning Human Understanding (1690) that reason must be our last judge and guide in everything, and in The Reasonableness of Christianity (1695) he argued that the faith is precisely what a reasonable person ought to accept. Locke did not reject revelation. He held that God could reveal truths reason could not discover, but that reason must judge whether a claimed revelation really comes from God. Hume, no friend of Christianity, put the principle in a sentence that has been quoted ever since: 'A wise man, therefore, proportions his belief to the evidence.' And in 1877 the mathematician W. K. Clifford, in an essay called The Ethics of Belief, put it at its sharpest: 'It is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence.'

The Christian rationalist has texts too. 'Come now, let us reason together,' says the LORD in Isaiah 1:18, though the setting there is a lawsuit in which God brings charges against his people. Paul tells the Thessalonians, 'test all things. Hold fast to what is good' (1 Thessalonians 5:21). The Bereans are called noble-minded because they 'examined the Scriptures every day to see if these teachings were true' (Acts 17:11), and they did it to an apostle. John warns, 'do not believe every spirit, but test the spirits to see whether they are from God. For many false prophets have gone out into the world' (1 John 4:1). If faith is not answerable to evidence, how can anyone tell a true prophet from a false one?

That question is the rationalist's strongest point, and it is especially sharp where many of the students of this school live. In places where self-appointed prophets promise wealth and healing for a fee, where a new revelation arrives every year and a church splits over every one, a faith that refuses to test claims is a faith that can be robbed. The rationalist's concern is that the believer who says do not ask questions, only believe, is precisely the believer a deceiver is looking for. Notice that this was Celsus's charge against the second-century church, which Origen did not deny of some believers but laboured to make untrue. Christians who claim that their faith is true, the rationalist says, must be willing to show why, or they have no right to the word true.

Those who push this view furthest do sometimes arrive somewhere they did not intend. In England around 1700, writers such as John Toland, in Christianity Not Mysterious (1696), and Matthew Tindal, in Christianity as Old as the Creation (1730), argued that whatever in Christianity could not be shown by reason should be dropped, and they were left with a God who made the world and a moral law, and very little of Christ. This was deism. A century later Immanuel Kant, in Religion within the Boundaries of Mere Reason (1793), reinterpreted the faith as a system of morality. The defender of rationalism will answer that this shows only that those writers reasoned badly, not that reason was the wrong judge. That reply has force. But the history is worth knowing, because it shows what happens when the judge is reason as one generation happens to understand it.

Between these two positions lies the tradition that most of the church, in East and West, Catholic and Protestant, has actually held. It goes back to Augustine, who leaned on an Old Latin rendering of Isaiah 7:9, unless you believe you will not understand, to argue that faith comes first and understanding follows as its reward, and to Anselm of Canterbury, whose Proslogion of 1077 or 1078 was first titled Faith Seeking Understanding. The Systematic Theology track examines that formula and its textual history in its first module, in the lesson of that name, and it is not repeated here. Note only that the Hebrew of Isaiah 7:9, as the BSB renders it, is about standing firm: 'If you do not stand firm in your faith, then you will not stand at all.' The method does not rest on that verse alone.

The formula says something specific about the order of faith and reason. It does not say that faith forbids questions; it says that questions are asked from inside trust rather than from a position of neutral suspicion outside it. And it does not say that reason has nothing to offer the unbeliever. Thomas Aquinas, who held this view, distinguished truths about God that reason can reach, such as that God exists and is one, which he called the preambles of faith, from truths that only revelation can give, such as the Trinity and the incarnation. In the Summa contra Gentiles he explains that God revealed even the first kind, because otherwise few would know them, and only after a long time, and mixed with error. Reason can show that faith is not contrary to reason; it cannot produce faith.

Christian traditions have written this into their confessions. The First Vatican Council, in the constitution Dei Filius of 1870, taught that God can be known with certainty from created things by the natural light of reason, and it condemned both fideism and the rationalism that would make faith depend on reason alone. Pope John Paul II's encyclical Fides et Ratio (1998) opens with the image that faith and reason are like two wings on which the human spirit rises to the contemplation of truth. On the Protestant side the Westminster Confession of Faith (1646), in its first chapter, lists the excellencies of scripture by which it abundantly evidences itself to be the word of God, and then adds that our full persuasion of its truth comes from the inward work of the Holy Spirit bearing witness by and with the word in our hearts. Lutheran theologians drew a useful distinction between the ministerial use of reason, where reason serves faith in understanding, ordering and defending it, and the magisterial use, where reason sits as judge over what God may say. The first they welcomed; the second they refused.

Here is what is settled across the whole church: reason is a gift of God, to be loved with the rest of us ('Love the Lord your God with all your heart and with all your soul and with all your mind', Matthew 22:37); faith is not believing without grounds; faith is not the conclusion of a syllogism either; and no one comes to saving faith by argument alone. And here is what is not settled. Christians still disagree about how much fallen human reason can know of God unaided. Roman Catholic teaching and the classical apologists give it more room; Barth, and the presuppositional apologists you met in the last lesson, give it much less; Reformed epistemologists hold that believers need no argument at all to be rational, while welcoming arguments where they help. Those disagreements are real, and they are why the previous lesson gave five methods rather than one.

Each extreme has also met its strongest objection, and each has a reply. Against strong fideism, critics ask how it can tell true faith from false, since a Muslim, a Latter-day Saint and a follower of a new prophet can all say that they simply believe, and the New Testament itself offers signs, witnesses and written records as grounds for faith (John 20:30-31; Acts 1:3; 1 Corinthians 15:3-8). Fideism's more careful defenders reply that they never meant to abolish testing, only to deny that faith's certainty grows or shrinks with the latest argument, and that the testing of a prophet is done by scripture, not by philosophy. Against strong rationalism, critics observe that Clifford's principle cannot meet its own standard, since there is no sufficient evidence for the claim that all beliefs need sufficient evidence, and that it would condemn most of what everyone rightly believes on trust, from the testimony of a doctor to the love of a spouse. Rationalists reply that this refutes only Clifford's overstatement, and that responsible belief, proportioned to the grounds available to a person, remains a real duty. Both replies are serious, and the middle tradition has learned from both.

If apologetics does not produce faith, what does? Scripture's answer is plain: the Holy Spirit. Jesus says of the Spirit, 'And when He comes, He will convict the world in regard to sin and righteousness and judgment' (John 16:8). Paul says, 'The natural man does not accept the things that come from the Spirit of God. For they are foolishness to him, and he cannot understand them, because they are spiritually discerned' (1 Corinthians 2:14). The problem is not only that the unbeliever lacks information. It is that he does not want what the information points to, and only God can change what a person wants.

But notice how the Spirit works in these passages. He does not work instead of words. The gospel came to the Thessalonians 'not only in word, but also in power, in the Holy Spirit' (1 Thessalonians 1:5): not only in word, which means also in word. Jesus tells the disciples that the Spirit 'will testify about Me. And you also must testify' (John 15:26-27). John says, 'Even if we accept human testimony, the testimony of God is greater' (1 John 5:9), and he does not tell his readers to stop accepting human testimony. The Spirit uses the preached word, the reasoned answer and the changed life. He is the one who makes them land.

Calvin made this the centre of his account of how anyone comes to trust scripture. In the seventh chapter of the first book of the Institutes he argued that scripture is self-authenticating, and that its authority is sealed on our hearts by the secret testimony of the Spirit, which is stronger than any proof. In the eighth chapter he then set out the evidences for scripture's credibility at length, saying that they are useful aids once the Spirit's testimony is given, though they cannot replace it. William Lane Craig, in his book Reasonable Faith, draws a related distinction between knowing that Christianity is true, which for the believer rests on the Spirit's witness, and showing that it is true to someone else, which is the task of argument. On that view a believer may know the truth long before he can show it, and the apologist's arguments serve the showing, not the knowing.

Pentecostal and charismatic Christians, now a very large part of the church in Africa, Latin America and Asia, add something the older traditions sometimes neglected. Paul says his preaching came 'with a demonstration of the Spirit's power' (1 Corinthians 2:4), and the first believers prayed, 'enable Your servants to speak Your word with complete boldness, as You stretch out Your hand to heal and perform signs and wonders' (Acts 4:29-30). Many people in the global south have come to faith after a healing, a deliverance or an answered prayer, not after an argument, and that is part of the Spirit's witness to Christ. At the same time Jesus warned that 'Many will say to Me on that day, "Lord, Lord, did we not prophesy in Your name, and in Your name drive out demons and perform many miracles?"' and that he will say he never knew them (Matthew 7:22-23). Power is not self-interpreting. A sign points to Christ only when it is joined to the truth about Christ, and that is why word and power belong together.

This has a direct consequence for how you think about doubt, your own and other people's. A believer who cannot answer an objection has not thereby lost his faith, and you should never tell anyone that he has. 'I do believe; help my unbelief!' cried the father in Mark 9:24, and Jesus healed his son. Some of the disciples who worshipped the risen Christ on the mountain still doubted (Matthew 28:17), and Jesus gave them the Great Commission anyway. Jude tells the church, 'have mercy on those who doubt' (Jude 1:22). The Pastoral Ministry and Care track has a lesson on doubt that deals with the pastoral side. For the apologist, the point is this: you are not the Holy Spirit. Your task is to give a faithful and honest account. His task is to give faith. Knowing that will keep you from despair when an argument fails, and from pride when it succeeds.

In your defence notebook, turn to a fresh page and write at the top: Why I believe. You are going to write an honest account of your own faith in three parts, using the three Latin words from section 1.

Under the first part, write what you know: the facts about God and Christ that your faith rests on, as you would state them to someone who had never heard them. Under the second, write why you judge those things to be true, and be honest. Some of your reasons will be arguments or evidence you could explain; some will be the testimony of people you trust; some will be the experience of answered prayer or of God's presence. Write them all down, and mark which kind each one is. Under the third, write what it has meant in your life to trust God, in a few sentences, without exaggeration.

Now read the two sentences you wrote in the inquiry. Look at your second part again and ask which reasons you would like to make stronger. Choose one, write it at the bottom of the page, and write beside it which later lesson of this track you expect will help: the existence of God in module 2, the reliability of the Gospels and the resurrection in module 3, or the hard objections in module 4. When you reach your capstone, this page will remind you that your written defence is not a substitute for faith, but an account of it.

Finally, pray for one person you know who is struggling to believe. Do not write the name. Ask God to do for them what no argument can do, and ask him to make you ready to give the argument too.