“Man has held three views of his body,” writes C.S. Lewis in the “Eros” chapter of his 1960 book The Four Loves.

First there is that of those ascetic Pagans who called it the prison or the “tomb” of the soul, and [others] to whom it was a “sack of dung,” food for worms, filthy, shameful, a source of nothing but temptation to bad men and humiliation to good ones. Then there are the Neo-Pagans, the nudists and the sufferers from Dark Gods, to whom the body is glorious. But thirdly we have the view which St. Francis expressed by calling his body “Brother Ass.”

Lewis then says, “All three may be . . . defensible; but give me St. Francis for my money.” He continues,

Ass is exquisitely right because no one in his senses can either revere or hate a donkey. It is a useful, sturdy, lazy, obstinate, patient, lovable and infuriating beast; deserving now a stick and now a carrot; both pathetically and absurdly beautiful. So the body. (93)

And so we now move to address the topic of body stewardship, which may seem like a surprising turn in our spring chapel series on the virtues. And, as Lewis saw 60 years ago in his day (and as he summarized three main enduring views of the human body throughout history), so we see them too today. We have our ascetic Pagans, or digital Pagans, who feel their body to be a prison. The body holds them back; screens and virtual reality create new possibilities. Life, for many, has become shockingly sedentary.

On the other hand, those same screens show image after image of meticulously sculpted and enhanced bodies — Lewis’s Neo-Pagans, half-nudists, at least, for whom the body is glorious, or must be glorious no matter how much dieting and exercise and surgery it takes.

And third, we have the road perhaps least traveled. Saint Francis’s road. Lewis’s road. Our road — the road of Christian Hedonists — Christian Hedonists. Today’s non-Christian hedonists may divide themselves up pretty well between sedentary, digital Paganism and semi-exhibitionist Neo-paganism, while we Christian Hedonists are gladly left with “Brother Ass.”

Now, I know the word Ass is arresting and hard to ignore. It accents our natural, sinful laziness and obstinance — the “infuriating beast” deserving the stick, as Lewis says. But I don’t want you to miss the affection and warmth in the word Brother. I don’t think Lewis says “Brother” lightly. Just as Jesus doesn’t say “brother” lightly. I don’t say it lightly. Brother accents the usefulness, sturdiness, patience, and lovability of these bodies, which are, Lewis says, “absurdly beautiful.” And he steers a careful course between reverence and beauty — they are not to be revered, but acknowledged and appreciated as “absurdly beautiful” — or as the psalm says, “fearfully and wonderfully made” (Psalm 139:14).

As Christian Hedonists

Let me just say, I’m a pastor (and adjunct professor). I’m not a personal trainer. I am not a dietician. In fact, I don’t know if I have anything to say here about diet — except a general plug for moderation, and a general warning about drinking sugar — but as a Christian Hedonist, I do have an interest in how the body serves not just natural joy but supernatural joy. And because this is a college and seminary chapel, it might be good to say something about the mind as well. And I hope, as Christian Hedonists, that the flavor of these next few moments would feel far more like the carrot than the stick.

“Working and pushing these bodies, as God designed them, serves Christian learning, joy, and love.”

Question One of the Heidelberg Catechism asks, as many of you know, “What is your only comfort in life and in death?” The answer is this: “That I am not my own, but belong — body and soul, in life and in death — to my faithful Savior, Jesus Christ.” We could talk about how the soul affects the body. But in these moments together, I’d like to focus on stewarding the body — and in particular moving the body, exercising the body, even training the body — in service of the soul.

So let me take you to one of many important texts in the Bible on the body, make some observations, and then consider how working and pushing these bodies, as God designed them, serves Christian learning, and Christian joy, and Christian love.

First Corinthians 6, start in the middle of verse 13:

The body is not meant for sexual immorality, but for the Lord, and the Lord for the body. And God raised the Lord and will also raise us up by his power. . . . Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own, for you were bought with a price. So glorify God in your body. (1 Corinthians 6:13–14, 19–20)

Four observations:

1. Your Body Is for Jesus

“For the Lord” means for drawing attention to Jesus, for making Jesus look good. Verse 13: “your body is for the Lord.” Verse 20: “So glorify God in your body.” We are made, Genesis 1 tells us, in the image of God. Images are irreducibly visible. We were made to image the invisible God in his visible world — to draw attention to him, not have it terminate on ourselves.

As Jesus says in Matthew 5:16, “Let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven.” Speak in such a way, and live in such a way in these bodies that others see what you do in your body — they see your good deeds — and they give glory, not to you, not to your body, but to your Father in heaven, and his Son, Jesus Christ.

2. Jesus Is for Your Body

He designed it. He gave it. He took a human body himself — and still has it. He is for your body’s good. Which means he is for us stewarding our bodies well. He is not against some modest efforts at upkeep. He is for that — wind in our sails.

3. God Will Raise Your Body

He raised Jesus’s body. Jesus is the firstfruits; we are the harvest. If you are in Christ, God will raise your body, and glorify your body. It will be changed, and far better, when he raises it. But it will be your body and modest upkeep now, especially in the service of learning and joy and love, is not a waste.

4. God Dwells Now in Your Body

If you are in Christ, you have the Holy Spirit. He is “within you.” Your body is a temple, a dwelling place, for God. So your body is yours but not “your own.” You didn’t make it. God did. You didn’t buy it back from sin and Satan; Jesus did. And you don’t dwell alone in it; God the Spirit dwells “within you.”

Consider, then, how working and pushing these bodies, as God designed them, serves Christian learning, and Christian joy, and Christian love.

For Christian Learning

As I have aged, I’ve sensed more and more tangibly how much better I feel after I’ve exercised. And in particular, I feel like I can think clearer, and more effortlessly, and more creatively. I feel like I have more energy, not only to move but to think and work hard with my mind. But is this just in my head, or is it real? I’ve heard other people talk about it too, but I want more clarity about my perceived mental clarity.

A few years ago, I found a book by a professor of psychiatry at Harvard Medical School, John Ratey. He had spent most of his career on ADHD and co-written some of the key texts on ADHD. He was a former amateur athlete and took notice over the years of what amazing medicine exercise proved to be for his patients. So eventually, he put his findings together in the 2008 book Spark: The Revolutionary New Science of Exercise and the Brain. Now, if any of this sounds too good to be true, remember what his prescription is: exercise. Apparently, many want to just take a pill. Few want to exercise. Here’s how he opens the book,

We all know that exercise makes us feel better, but most of us have no idea why. We assume it’s because we’re burning off stress or reducing muscle tension or boosting endorphins, and we leave it at that. But the real reason we feel so good when we get our blood pumping is that it makes the brain function at its best, and in my view, this benefit of physical activity is far more important — and fascinating — than what it does for the body. Building muscles and conditioning the heart and lungs are essentially side effects. I often tell my patients that the point of exercise is to build and condition the brain. (3, emphasis added)

He continues, “To keep our brains at peak performance, our bodies need to work hard” (4). “The brain responds like muscles do, growing with use, withering with inactivity” (5) — and movement activates the brain. And Ratey explains how it is that exercise improves learning — which matters to us as Christians. We call ourselves disciples, which means learners. Christianity is a teaching movement, and a learning movement — in Christ, we are no less than lifelong learners. Learning matters to me as a pastor and editor and adjunct professor. And I hope it matters to you as a student, and as a Christian. So, here’s “how exercise improves learning on three levels”:

first, it optimizes your mind-set to improve alertness, attention, and motivation; second, it prepares and encourages nerve cells to bind to one another, which is the cellular basis for logging in new information; and third, it spurs the development of new nerve cells. . . . (53)

Active bodies improve learning. I’ll say more in a minute about how. But there’s the first reason: for Christian learning. Second, then, for Christian joy — that is, natural joy leading to supernatural joy.

For Christian Joy

Hippocrates, the father of medicine (four centuries before Christ), said, “Eating alone will not keep a man well; he also must take exercise.” Hippocrates also learned to treat depression with a long walk. And if that didn’t seem to help, he advised taking another: “Walking is the best medicine,” he said — in the pursuit of joy, a happy soul.

One of the key truths for which we stand at Bethlehem College & Seminary and Desiring God — and perhaps the most distinctive one — is that we believe enjoying God is essential to glorifying God as we ought. To be bored or uninterested in him is to dishonor him, whatever motions we go through with our bodies. And so, vital for our fulfilling the very purpose and calling of our lives is our enjoying, delighting in, being satisfied, in our souls, with who God is for us in Christ.

In terms of the carrot, the angle that has proved most helpful for me over the years in motivating and sustaining body stewardship through regular exercise is reckoning with how it supports the pursuit of joy in God. The little bit of intense exercise that I do is, in its highest and best form, about enjoying God, which glorifies him.

Getting Energy from Expending Energy

I am not mainly motivated by living longer. “To depart and be with Christ . . . is far better” (Philippians 1:23). And I am not motivated much by looking fit and healthy. For me, those motivations are inadequate. For me, the driving motivation under the banner of enjoying more of God is the energy I get from expending energy. And that’s first emotional energy (we’ll talk about the other in a minute). When I exercise regularly, I feel better. Not only do I feel like I think clearer, but I seem to sleep better, and I’m generally happier.

“Regular exercise puts my body and soul into a better position to clearly see and deeply savor who God is in Christ.”

Regular exercise puts my body and soul — and their complicated and mysterious relationship — into a better position to clearly see and deeply savor who God is in Christ. And so I want to put natural joy (and alertness and attention and energy and resilience) to use to serve spiritual, Christian, supernatural joy.

I said I’d say more about how this works — how bodily movement and exertion serve our natural joy. Back to the Harvard psychiatrist, who says,

Going for a run is like taking a little bit of Prozac and a little bit of Ritalin because, like the drugs, exercise elevates these neurotransmitters. It’s a handy metaphor to get the point across, but the deeper explanation is that exercise balances neurotransmitters — along with the rest of the neurochemicals in the brain. (38)

Miracle Grow for the Brain

But let’s go one step deeper, and stop here. Knowing a little bit of the mechanism helps me:

“BDNF [Brain Deprived Neurotrophic Factor, “Miracle Grow” for the brain] gathers in reserve pools near the synapses and is unleashed when we get our blood pumping. In the process, a number of hormones from the body are called into action to help. . . . During exercise, these factors push through the blood-brain barrier, a web of capillaries with tightly packed cells that screen out bulky intruders such as bacteria. . . . [O]nce inside the brain, these factors work with BDNF to crank up the molecular machinery of learning. They are also produced within the brain and promote stem-cell division, especially during exercise. . . . The body was designed [!] to be pushed, and in pushing our bodies we push our brains too. (51–53)

We know that “bodily training is of some value,” and godliness all the more (1 Timothy 4:8) — but one of the reasons I take “bodily training” with such seriousness, rather than ignoring it, is precisely because of how it serves the joy and strength and stability of my soul.

So, there’s the Harvard psychiatrist. What about Christian voices? Well, I haven’t been aware of many, at least in our circles, over the years. But I did edit a chapter one time on exercise in a book called Brothers, We Are Not Professionals. The chapter was called “Brothers, Bodily Training Is of Some Value.”

John talks there about “the correlation between the condition of the body and the condition of the soul” (183); he says that “consistent exercise has refining effects on our mental and emotional stability” (185). And one of the motivations he points to, and now other Christian voices are chiming in, is energy — in the service of doing good for others. So not just Christian learning, and Christian joy, but finally Christian love.

For Christian Love

Not only does regular exercise make me feel like I think clearer, and I feel happier, and more ready to pursue spiritual joy, but I also feel stronger and more ready to exert bodily effort, whether mental or physical, for the sake of others. I’ve also found that pummeling or disciplining (Greek hupōpiazō) my body, as Paul says in 1 Corinthians 9:27, strengthens my will, and chases away laziness, in all of life. Regular exercise makes me more active, rather than passive or lazy, in every sphere and every relationship — not the least of which is relating to God through his word and prayer. But also for others.

Too Tired to Love

Here are the other voices. In 2019, we published a short article at Desiring God, called “Remember the Body,” by pastor Mark Jones in Vancouver, speaking, like Piper, to fellow pastors, with clearly broader applications:

Physical exertion is an important part of normal human life. . . . [I’m] persuaded that a lot of pastors should jump on a bike, go for a run, walk, or build some modest muscle, and they’d likely get more work done. A lack of discipline in areas such as food, exercise, and drink typically reflects a lack of discipline in other areas of the Christian life. . . . Exercise is a friend [Brother?] of the Christian, and one that, unless prohibited by health reasons, should be part of the ordinary Christian life.

About the same time, I came across the 2017 Crossway book Reset by David Murray, pastor and professor. He says, “Exercise and proper rest patterns generate about a 20 percent energy increase in an average day, while exercising three to five times a week is about as effective as antidepressants for mild to moderate depression” (79).

Finally, in his late 2020 book on church leadership, Paul Tripp writes about his newfound appreciation for stewarding well the bodies God gave us. He realized, beginning with himself, that “widespread church and ministry leadership gluttony is robbing us of both gospel consistency and physical energy.” He continues,

Regular exercise boosts and builds energy. Perhaps many of us are tired all the time not because of the rigorous demands of ministry but because of the lack of rigorous physical exercise in our normal routine. . . . [T]hese are not ancillary issues. (Lead, 82)

Modest Path

Now, before we get going down any Neo-Pagan paths, let’s bring it back to “Brother Ass” — beloved, obstinate, useful, not revered and not hated, pathetically and absurdly beautiful, Brother Ass.

Mark Jones uses the word modest which I appreciate. He says, “build some modest muscle” — which I think will serve most of us well in our age of extremes related to our bodies. On the one hand, we feel the pull of our world’s sedentary patterns: riding in cars, mesmerized by screens. We have indulged ancient instincts, designed for days when food was scarce, to intuit how to move as little as possible. But thank God, we’re not living in times of famine. Just deadly excess.

On the other hand, we find the fitness junkies, pushing back against sedentary assumptions, but for what reason? “Well-being” as enjoying life more today, not just someday far off, is doubtless more honorable than a brazen pursuit of self-glory. But as Christians we have more to say, critically more, about fitness as stewarding these remarkable creations of our Lord we call bodies.

Fit for What?

I do think “fitness” is a word we can work with as Christians. We just need to ask, Fit for what? Fit to draw attention on Instagram? Fit to draw eyes on a stage, or half-clad? Or fit to do others good? Fit to live up to the modest and important calling we have as Christians to love others and use these bodies to serve and bless and help others?

Paul twice uses a phrase — in 2 Timothy 2:21 and Titus 3:1 — that might be a good rallying cry for the modest upkeep of these physical bodies: “ready for every good work.”

We not only want to learn well, which is critical for disciples. And we not only want to have spiritual joy, which is critical in glorifying Jesus as we ought. We also want to fulfill our calling to use these bodies to do others good — and in such a way that others see our good works, in these bodies, and do not give glory to us but to our Father in heaven, and to Jesus.

“We tend to overestimate what can be done in the short run, and underestimate what can be done in the long run.”

And for most of us, we will be well served by modest upkeep. Subtle changes in our default mindset about minimizing movement, or learning to enjoy it. Walking counts; it gets the blood pumping. Small steps over the long haul. Walking for 30 minutes, five times week, would fulfill the recommendation of many of the experts. And if over time, your body was in enough shape to enjoy regular 30-minute walks, you might find exercise to be an acquired pleasure and enjoy some weights or jogging as well. But we tend to overestimate what can be done in the short run, and underestimate what can be done in the long run.

Brothers and sisters, your body, as a priceless gift from God, is “both pathetically and absurdly beautiful.” It is “a useful, sturdy, lazy, obstinate, patient, lovable and infuriating beast; deserving now the stick and now a carrot.” As Christian Hedonists, let’s pursue the carrots of Christian learning, Christian joy, and Christian love.