Summary: A summary of the "Christian Behavior" section of C. S. Lewis’ classic Mere Christianity

The Life and Legacy of C. S. Lewis #3

“Mere Christianity (part 2)”

Philippians 2.1-13

C. S. Lewis’ book Mere Christianity is important not only because of the way it articulates what Christians believe (and why) but how we are to behave (and why). In fact twelve chapters of the book are devoted to exploring Christian Behavior. Lewis acknowledges at the outset that what he has to say may be a tough sell by describing a schoolboy who believed that God was “the sort of person who is always snooping around to see if anyone is enjoying himself and then trying to stop it.” (1) Many people (Lewis once included) experience morality as interference. In reality, moral rules are gifts that reduce individual stress and strain and prevent breakdown, strain and friction.

Morality is concerned with three things: relationships between people, individual character, and the purpose for which we were created. Most popular thought on morality focuses on how people get along but Lewis wisely notes that the ultimately root of morality is in the individual. “What is the good of drawing up, on paper, rules for social behavior,” he asks, if we know that, in fact, our greed, cowardice, ill temper and self-conceit are going to prevent us from keeping them?” (2) His profound honor for human beings created in the image and likeness of God offers a strong philosophical foundation (which humanism lacks) for a recognition of universal human rights. “If individuals live only seventy years,” he writes, “then a state, or a nation, or a civilization, which may last for a thousand years, is more important than an individual. But if Christianity is true, then the individual is not only more important but incomparably more important, for he is everlasting and the life of a state or civilization, compared with his, is only a moment." (3)

Lewis then goes on to consider what are historically regarded as the seven virtues. Four of those are the cardinal virtues (cardinal comes from a word meaning “door hinge” and refers to that which is “pivotal”). These are prudence (practical common sense), temperance -you can be just as intemperate about golf, clothes or bridge as alcohol, Lewis notes. “God is not deceived by externals.” (4)- justice (which includes fairness, honesty, give and take, truthfulness, and keeping promises) and fortitude (courage). He notes, “There is a difference between doing some particular just or temperate action and being a just or temperate [person]. Someone who is not a good tennis player may now and then make a good shot… A man who perseveres in doing just actions gets in the end a certain quality of character. Now it is that quality rather than the particular actions which we mean when we talk of virtue.” (5)

Moving on to social morality, Lewis notes that “Christianity has not, and does not profess to have, a detailed political program for applying ’Do as you would be done by’ to a particular society at a particular moment. It could not have. It is meant for all [people] at all times…" (6)Nonetheless there are hints from scripture as to what a Christian society might look like. Lewis lists three likely elements: (a) There would be no passengers or parasites (people would work to create good things); (b) there would be no “putting on airs” by which I assume he means no social pomposity or presumption; and (c) it would be a cheerful society. Noting that a Christian society would be an unprecedented melding of liberal and conservative values, Lewis notes, “We have all departed from that total plan in different ways, and each of us wants to make out that his own modification of the original plan is the plan itself… That is why we do not get much further: and that is why people who are fighting for quite opposite things can both say they are fighting for Christianity." (7)

One aspect of social morality that Lewis took especially seriously was giving. He did not just tithe; he gave over 80% of his money to people in need, churches and charitable causes. In Mere Christianity he gives this guideline: “I do not believe one can settle how much we ought to give. I am afraid the only safe rule is to give more than we can spare. In other words, if our expenditure on comforts, luxuries, amusements, etc. is up to the standard common among those with the same income as our own, we are probably giving away too little. If our charities do not at all pinch or hamper us, I should say that they are too small. There ought to be things we should like to do and cannot do because our charities expenditures excludes them." (8) The great obstacle to our giving as we could, he says, is fear of insecurity.

Lewis devotes a chapter to Morality and Psychoanalysis. He notes that when Freud writes about “how to cure neurotics he is speaking as a specialist on his own subject, but when he goes on to talk general philosophy he is speaking as an amateur. It is therefore quite sensible to attend to him with respect in the one case and not in the other– and that is what I do. I am all the readier to do it because I have found that when he is talking off his own subject and talking on a subject I do know something about (namely language) he is very ignorant. But psychoanalysis itself, apart from all the philosophical additions that Freud and others have made to it, is not… contradictory to Christianity.” (9) That’s because, when we make moral choices, two things are involved: an act of will and our feelings, impulses, and so on. When the latter aren’t functioning properly, we might need help exploring why so that we can do something about it.

Some people, Lewis notes, think of morality as a kind of bargain we make with God where God rewards us for doing the right thing. Lewis suggests an different, more nuanced view: “Every time you are making a choice, you are turning the central part of you, the part of you that chooses, into something a little different than it was before. And taking your life as a whole, with all your innumerable choices, all your life you are slowly turning this central thing either into a heavenly creature or into a hellish creature: either into a creature that is in harmony with God, and with other creatures, and with itself, or else into one that is in a state of war and hatred with God, and with its fellow creatures, and with itself… Each of us at each moment is progressing to the one state or the other." (10) Again, the issue is not merely our individual choices, but what the kind of character we are developing and the kind of people we are ultimately becoming.

Lewis next turns to Sexual Morality. "Chastity is the most unpopular of the Christian virtues,” he writes. “There is no getting away from it; the Christian rule is, ’Either marriage, with complete faithfulness to your partner, or else total abstinence.’ Now this is so difficult and so contrary to our instincts, that obviously either Christianity is wrong or our sexual instinct, as it now is, has gone wrong. One or the other." Arguing that something has gone wrong with our instinct, he makes his point by asking us to imagine “a country where you could fill a theatre by simply bringing a covered plate on to the stage and then slowly lifting the cover so as to let everyone see, just before the lights went out, that it contained a mutton chop or a bit of bacon… [W]ould you not think that in that country something had gone wrong with the appetite for food?" (11)

There are three reasons why it’s hard for us to desire chastity. (a) It feels as if it is almost abnormal to resist desires that seem so natural. "Like all powerful lies, it is based on a truth– the truth… that sex in itself… is normal and healthy… The lie consists in the suggestion that any sexual act to which you are tempted at the moment is also healthy and normal." (12) (b) We think it’s not possible. (c) Psychology teaches that repressed sex is dangerous. But repressed is a technical term, Lewis notes, and does not mean suppressed which, rather than being dangerous, is good and healthy. Even so, he says, "I want to make it as clear as I possibly can that the center of Christian morality is not here… The sins of the flesh are bad, but they are the least bad of all sins. All the worst pleasures are purely spiritual… There are two things inside me, competing with the human self which I must try to become. They are the Animal self, and the Diabolical self. The Diabolical self is the worse of the two." (13)

Following a chapter on Christian Marriage in which he argues that Christian marriage is for life, that divorce is more like an amputation than dissolving a business partnership, and that ceasing to be in love need not mean ceasing to love, Lewis tackles the topic of forgiveness which, he allows, may be an even less popular virtue than chastity. In this chapter he asks a question many of us struggle with, how it is possible to “hate the sin and love the sinner.” His response is remarkable. "For a long time I used to think this a silly, straw-splitting distinction: how could you hate what a man did and not hate the man? But years later it occurred to me that there was one [person] to whom I’ve been doing this all my life– namely myself. However much I might dislike my own cowardice or conceit or greed, I went on loving myself. There had never been the slightest difficulty. In fact the very reason why I hated the things was that I loved the man." (14) If you’re struggling with forgiving someone, this chapter will help.

One of Mere Christianity’s most influential chapters is on The Great Sin. Reading this chapter of Mere Christianity brought Chuck Colson to faith in Christ. The great sin is pride. "Unchastity, anger, greed, drunkenness, and all that, are mere flea bites in comparison,” he notes. “It was through pride that the devil became the devil. Pride leads to every other vice. It is the complete anti-God state of mind.” While other sins may accidentally create competition between people, pride is essentially competitive. Other vices may bring people together, but pride always creates enmity not just between people but between us and God. The most dangerous form of pride is spiritual pride (which both believers and unbelievers share) because through it we can consider ourselves more virtuous or insightful than others. "The other, and less bad, vices come from the devil working through our animal nature. But [pride] does not come through our animal nature at all. It comes direct from Hell. It is purely spiritual: consequently it is far more subtle and deadly … The devil laughs,” Lewis says. “He is perfectly content to see you becoming chaste and brave and self-controlled provided, all the time, he is setting up in you the Dictatorship of Pride." (16)

Lewis then goes on to discuss the three theological virtues: faith, hope and charity. Charity refers to love in the Christian sense. We can choose to love those whom we would not otherwise naturally like and, loving them, come to like them. Love is not an emotion but a choice or an act of will that can have lasting and even eternal consequences. Writing as he was during World War II, Lewis easily used spiritual warfare language to make his point: "Good and evil both increase at compound interest. That is why the little decisions you and I make every day are of such infinite importance. The smallest good act today is the capture of a strategic point from which, a few months later, you may be able to go on to victories you never dreamed of. An apparently trivial indulgence in lust or anger today is the loss of a ridge or railway line or bridgehead from which the enemy may launch an attack otherwise impossible." (17)

In his chapter on Hope Lewis addresses the hackneyed idea that Christians long for “pie in the sky.” Quite the opposite. "If you read history,” he notes, “you will find that the Christians who did most for the present world were just those who thought most of the next… Aim at Heaven and you will get earth thrown in: aim at earth and you will get neither." (18) As to why we long for heaven, Lewis makes a memotrable observation which has come to be known as “The Argument from Desire.” “’Creatures are not born with desires unless satisfaction for those desires exists,” he writes. “A baby feels hunger: well, there is such a thing as food. A duckling wants to swim: well, there is such a thing as water. Men feel sexual desire: well, there is such a thing as sex. If I find in myself a desire which no experience in this world can satisfy, the most probable explanation is that I was made for another world." (19)

As for Faith, Lewis points out that the word can have two meanings. One is belief, he other is "the art of holding on to things your reason has once accepted, in spite of your changing moods. For moods will change, whatever view your reason takes.” (20) There are two specific things we can do to keep our changing moods from dominating us. First there are spiritual disciplines like daily prayers, religious reading, and attending worship so we can be reminded what we believe. Second is a serious attempt to practice the Christian virtues. (A week is not enough, Lewis suggests. Try six.) "No man knows how bad he is till he has tried very hard to be good. A silly idea is current that good people do not know what temptation means. This is an obvious lie. Only those who try to resist temptation know how strong it is. After all, you find out the strength of the German army by fighting against it, not by giving in… That is why bad people, in one sense, know very little about badness. They have lived a sheltered life by always giving in." (21)

Followers of Jesus Christ believe certain things. They also behave in a certain way. Why the focus on Christian behavior? Lewis answers, "What God cares about is not exactly our actions. What he cares about is that we should be creatures of a certain kind or quality– the kind of creatures He intended us to be– creatures related to Him in a certain way." (22) “Christianity seems at first to be all about morality, all about duties and rules and guilt and virtue,” Lewis says, “yet it leads you on, out of all that, into something beyond. One has a glimpse of a country where they do not talk of those things, except as a joke. Everyone there is filled full with what we should call goodness as a mirror is filled with light. But they do not call it goodness. They do not call it anything. They are not thinking of it. They are too busy looking at the source from which it comes.” (23) That which matters so much here– and should– it seems will be like the air we breathe when we are one day “lost in wonder, love, and praise.”


1 C. S. Lewis, Mere Christianity, (Harper: San Francisco), p.69.

2 Ibid., p. 73

3 Ibid., pp 74-75.

4 Ibid., p. 79.

5 Ibid., pp. 79-80

6 Ibid., p. 82.

7 Ibid. p. 85.

8 Ibid., p. 86.

9 Ibid., p. 89.

10 Ibid., p. 92.

11 Ibid., p. 96.

12 Ibid., p. 100.

13 Ibid., p. 103.

14 Ibid., p. 117.

15 Ibid., p. 122.

16 Ibid., p. 125.

17 Ibid., p. 132.

18 Ibod., p. 134.

19 Ibid, p. 137.

20 Ibid, p. 140.

21 Ibid., p. 142.

22 Ibid., p. 145.

23 Ibid., pp149-150.