‘Mere Christianity’: A Simple Defence of the Faith
A review of ‘Mere Christianity’, by C.S. Lewis; HarperOne, 1952.
C.S. Lewis’s Mere Christianity is a slim book with a broad aim: to explain and defend the Christian faith. It was adapted from a series of BBC radio talks Lewis gave during the Second World War, and has the authority of the Oxford don but is expressed with the plainness of a man speaking to ordinary people. Lewis paints a picture of Christianity stripped of sectarian squabbles, presenting a faith that is less about ceremony and more about substance.
There are four parts. First, Lewis sets out his moral argument for God. He contends that we human beings have an in-built sense of right and wrong. Across cultures, we agree that some actions are acceptable and others not. Of course, we often do the wrong thing (and/or fail to do the right thing), but the fact is that we know what is right and wrong. This points to a standard of morality that lies beyond ourselves. What, then, is the source of this moral law? Lewis suggests the fount of this universal morality is a higher power, a lawgiver. He calls this God.
First, Lewis sets out his moral argument for God. He contends that we human beings have an in-built sense of right and wrong.
Christians believe particular things about this God. In the second part, Lewis takes a look at them. God, for Christians, is both good and personal. He is not an abstract force but a loving, just and holy being who cares actively for His creation. His goodness is absolute, which makes him the final standard for morality and justice. But, as I have suggested above, we don’t always live up to this standard. Humanity, says Lewis, has fallen into a state of sin. This is not mere wrongdoing, but a basic rebellion against God’s will, a refusal to act in line with his wishes. Thus sin is an assertion of self-centredness. It is rooted in our doing what we want to do, rather than what God wants us to do. It separates us from God, which leads to spiritual and moral corruption. It leaves us in need of redemption.
But we cannot save ourselves through good deeds or moral effort—though those help. Salvation is an act of grace from God, offered through the person and the work of His son. So Christ, says Lewis, is key. (The clue is in the name of the religion.) Christ, for Christians, was not a moral teacher or prophet, not a charismatic preacher in Bronze-Age Palestine, but the Son of God. This matters because only God can bridge the infinite gap between His innate holiness and our innate sinfulness. Christ walked among us to reveal God’s character in a way that we could understand. Through His teachings, miracles and actions, Christ acted out God’s love, justice and mercy. By living a sinless life and offering himself up as a sacrifice for the sins of the world, Christ reconciled humanity to God. Through substitutionary atonement, Christ paid the penalty for sin, making forgiveness and restoration possible for all who accept it. The Resurrection was the ultimate proof of Christ’s divine nature. It demonstrated victory over sin and death and offered believers the promise of eternal life.
Christ, for Christians, was not a moral teacher or prophet, not a charismatic preacher in Bronze-Age Palestine.
Lewis then introduces his ‘Trilemma’. He addresses this to those who admire Jesus as a great moral teacher, akin to, say, Socrates, but deny His divinity. Lewis contends that this position is logically inconsistent because of the claims Jesus made for Himself. Jesus forgave sins (which is reserved for God); claimed unity with the Father (‘I and the Father are one’); and accepted worship from others. Given these claims, Lewis makes his ‘Lunatic, Liar, Lord’ argument:
- If Jesus was not divine but claimed to be, He must have been a Lunatic, on par with someone thinking himself to be Napoleon.
- If He knew He was not divine but tricked others into believing he was, then He would be a Liar, trashing the integrity basic to moral teaching.
- If He was neither a Lunatic nor a Liar, then he must be Lord—in other words, who He claimed to be.
So, says Lewis, accepting Jesus as a merely moral teacher is unreasonable. We must either reject Him entirely or acknowledge His divinity. There is no middle ground.
Faith is not just about belief. Part three concerns Christian behaviour. To be a Christian is to live, or to try to live, a moral life in line with the will of God. Morality, for the Christian, is not a set of rules, but a reflection of the character of God and His design for human beings. True happiness and flourishing, says Lewis, is impossible if we do not obey God’s commandments. Among these are to cultivate the Cardinal and Theological Virtues: prudence (practical wisdom), temperance (self-control), justice (fairness), fortitude (courage); faith (trust in God), hope (confidence in His promises), charity (selfless love). The highest virtue is a selfless, sacrificial love (agape) that seeks the good of others and reflects God’s love for humanity.
Morality, for the Christian, is not a set of rules, but a reflection of the character of God and His design for human beings.
That is one side of the coin. The other side deals with sin. Pride is ‘the great sin’, says Lewis, and the root of all others. It leads to self-centredness, competition and warped sense of independence. Humility—its opposite—is not, for Lewis, thinking less of oneself, but ‘thinking of oneself less’. Pride appears as vanity, arrogance and selfish ambition. It destroys relationships, fuels envy and resentment and blinds us to our need for grace. Lewis argues that pride is at the heart of the rebellion against God, for it assumes—wrongly—that we do not need him. The sins that grow out of pride undermine the relation between humans and their Creator. They represent a turning away from God’s will.
Lewis defends sexual morality and the sanctity of marriage, which he views as a microcosm of the the union between God and His people. He also stresses the radical character of Christian forgiveness. Believers are called to forgive not just what is easy to forgive, but grave wrongs, including those committed by our enemies. This mirrors God’s forgiveness of humanity’s sins. To forgive is not to excuse wrongdoing or to let others off the hook. But it does mean letting go of hatred and the desire for revenge. That isn’t easy. Nor is fulfilling the command to love our enemies. Lewis explains that to do this is not to like our enemies or approve of their actions, but to wish them well and treat them with respect and kindness. Selfless love, charity, is the heart of Christian action: not just being good, but doing good. Lewis says we will often fail to live up to these standards of behaviour, but that we are duty-bound to keep trying.
To forgive is not to excuse wrongdoing or to let others off the hook. But it does mean letting go of hatred and the desire for revenge.
Which brings us to the fourth part of Mere Christianity. This is where we get into the weeds. First, Lewis discusses the Nature of God. According to the Trinity, there is one God in three persons: Father, Son and Holy Spirit. Our relationship with God is not with three separate gods but a unity-in-diversity. Lewis likens this concept to dimensions of space. A cube has three dimensions (length, breadth and height) that are distinct but inseparable. So too does the Trinity consist of three distinct persons who are also united.
And unity is key. For God is relational. The love that exists within the Trinity, between its three persons, establishes God’s nature. Lewis explains that this love is a kind of dance of self-giving and eternal connection. By understanding God as relational, Lewis underscores the idea that love and community are fundamental to reality. (More and more, quantum science, with its findings about the observer effect, wave-particle duality and entanglement, call into question the materialist conception of reality, suggesting that, at bottom, reality really is relationship.) Human beings, Lewis says, reflect this relational character.
And unity is key. For God is relational. The love that exists within the Trinity, between its three persons, establishes God’s nature.
For Lewis, Christianity is ultimately about our transformation into a new kind of being. Being good, following rules, etc. etc. are means to participate fully in God’s divine life, which Lewis views as becoming more like Christ. Through His life, death and resurrection, He not only reconciled humanity to God but gave us a model of perfect love and obedience. By uniting with Christ, by being like Him, we share in His divine nature and begin the process of spiritual renewal. We move from a flat, two-dimensional existence to a fuller, richer, three-dimensional life. We become a different kind of human: our most complete, most human selves, humans as God intended.
And this takes faith: not blind belief, but an active trust in God. When life is tricky, or when circumstances get in the way, we must commit and recommit consciously. Obedience, prayer, the pursuit of virtue—this kind of active engagement deepens our trust in God and strengthens our relationship with him, so that when the chips are down we are stronger in our conviction that things will work out in the end. Through these expressions of faith, says Lewis, we open ourselves up to grace, which enables us to overcome our limitations and grow. It goes without saying that faith ultimately transcends reason. We choose to trust in what is beyond our comprehension.
Obedience, prayer, the pursuit of virtue — this kind of active engagement deepens our trust in God.
Taken on the whole the book is a defence of the reasonableness of faith. Lewis is convinced that Christianity makes sense of the world’s contradictions: the beauty of creation, the cruelty of history, the stubborn persistence of human decency even when it does not seem possible. He argues from the ordinary, from common-sense principles. ‘If I find in myself a desire which no experience in this world can satisfy,’ he writes, ‘the most probable explanation is that I was made for another world.’ Such a thought captures very simply his style: understated, vivid, rational, human.
And simple. Lewis takes an approach that is ecumenical and intuitive, employing an everyday style of reasoning from first principles and resisting the logic-chopping of the academic philosopher. Consequently he speaks both to heart and mind. He writes not as a philosopher or theologian or even as a novelist. He writes as a kind of fellow pilgrim, keenly aware of his own flaws and limits. The appeal of the book lies in its clarity, warmth, earnestness and humility. There is no fire and brimstone here, but a call for more open hearts and open minds; and also for open eyes: for awe and for wonder.
