“And the LORD commissioned Joshua the son of Nun and said, ‘Be strong and courageous, for you shall bring the people of Israel into the land that I swore to give them. “I will be with you.” (Deut. 31:23)

I have often wondered if we should see physical fitness as a good option, a mandate, or, between the two, as a wise and biblical practice. I’ve hesitated to address this issue because I have a bias that, I fear, could incline me to legalism. I did some manual labor in my youth, but I’ve had the sedentary calling of a professor and pastor for many years. It’s easy to become flabby in a calling that demands so much sitting, talking, and typing and so little physical exertion. On the other hand, I love exercise and athletic competition—playing, not watching. I also believe that I need to exercise. If I go three days without it, my energy flags, concentration lags, and I can get irritible. So I know what need to do, but if I exhort a group to get in shape, am I a legalist, turning my good ideas and preferred practices into someone else’s law? Or am I reminding them of a forgotten part of God’s will?

With that question in mind, the commission “Be strong and be courageous” hit me with some force when I recently discovered that it appears at least 15 times in Scripture. Moses told all Israel to “be strong and courageous” as they prepared to enter the promised land. Then Moses (31:7) and the LORD himself (Deut. 31:23, Josh. 1:6, 7, 9) told Joshua the same thing. Soon enough, the people repeated it in Joshua 1:18. Later, David commanded Solomon, and Hezekiah charged all Israel to “Be strong and courageous” when a great task lay before them (1 Chron. 22:13, 28:20, 2 Chron. 32:7). Finally, Paul closed 1 Corinthians with the same command (1 Cor. 16:13). The message is always the same: God’s people can be strong and courageous, because God goes with them and fulfills his promises to them.

Spiritual and Metaphorical

It’s easy, in the context of God’s reassurances, to read the command “Be strong and courageous” in a spiritual and metaphorical sense. To be sure, the command is strictly spiritual in places like 1 Chronicles 28:20 and Psalm 31:24. But with recent debates about manhood and womanhood in my mind, the obvious hit me: If a man hopes to be courageous in battle, it helps if he feels literally, physically strong and capable. To be sure, the Lord can send panic and confusion into the ranks of heathen armies (Judges 8, 2 Kings 7), but that doesn’t always happen. It’s clear that David’s mighty men had both spiritual courage and physical strength to fight lions, giants, and superior numbers (2 Sam. 24:8-23). Similarly, David’s general Joab both trusted God and also expected to fight hard in 2 Samuel 10.

This observation doesn’t prove that everyone must be fit and strong. But since Israel had a citizen army, it does suggest that mature men were expected to have both the faith and also the strength to fight for God’s people when necessary. I must note that I say “men” for historical reasons—Israel’s army was male. I heartily commend fitness and strength for women and am deeply grateful that my wife and daughters have endurance, strength, and dexterity.

Someone may say that Jewish customs do not bind us, since, in the West, men and women rarely need physical strength for their daily work. We no longer stay strong through manual labor. But I don’t want to give up so quickly. First, we can surely see that God created humans with a capacity for strength. We notice how readily the body becomes stronger and faster with even modest exercise. We notice that men and women respect strength and are drawn to it. Yes, we can put too much stock in physical strength; Jeremiah 9:24 warns, “Let not the mighty man boast in his might.” But the very warning testifies that strength is desirable.

This study reminded me of the time I spoke at a men’s conference for a leading church in a smaller town. A local leader became my Saturday afternoon guide. As he drove me around, I asked him, “What defines a male as a real man in this town?” He replied, “A man knows he’s got it made when he has a good truck, a cabin on the river, and is an officer in the church. But if he can kill a deer with a bow at 50 paces, his name is assured.” Even if we live in a city and never draw a bow, we may feel the last point viscerally. God created us with a capacity to grow in skill and strength, and many of us yearn for it, even if we expect to show our strength in other ways. The “bow” statement can resonate because it labels a thread in God’s ideal for both women and men.

Evidence of Strength

There is evidence that God wants his people to be physically strong. The apostle Paul repeatedly compares believers to soldiers (2 Tim. 2:3-4) and likens the Christian life to a fight (1 Tim. 1:18). He says, “Fight the good fight of the faith” (1 Tim. 6:12). He says he buffets his body and tells the Corinthians to run the race so as to reach the prize (1 Cor. 9:24-27, cf. Heb. 12:1). Some scholars dismiss Paul’s references to fights, races, and training as a matter of taste. They say he liked athletics. But we can’t dismiss this theme so easily, because Paul commends physical training in 1 Timothy 4:8: “Physical training is of some value, but godliness has value for all things . . . both the present life and the life to come.”

Physical training doesn’t have supreme value, but Paul says it has “some value.” A review of Paul’s life shows the role of physical strength in his apostolic work. In Paul the Missionary, Eckhard Schnabel shows that Paul traveled 8,700 miles by land—on foot—during his known missionary journeys. If we remember the dangers and deprivations that Paul endured (see Paul’s list in 2 Corinthians 11), we know he had to be physically vigorous and resilient.

David, Israel’s archetypal king, was strong too. He killed a lion and a bear with his hands while tending his family’s flocks (1 Sam. 17). Jesus was a carpenter, so we know he worked with his hands. The Greek term translated carpenter, tekton, covers all who worked with wood, stone, and metal. In today’s terms, Jesus might have been a skilled construction worker. If he worked with arms and hands all day, he had to be physically impressive. He might have looked lean or wiry to us, but he had to be strong, a man with tough hands. Beyond that physical strength, there was something about Jesus that impressed people. Until his hour arrived, soldiers couldn’t manage to arrest him (John 7) and crowds, however hostile, could do him no harm (Luke 4). Jesus had strength of mind, character, and body. We are attracted to the combination.

Wise and Good

The biblical data may not mandate exercise, but it shows that it’s wise and good to be strong. Paul says physical training has value (1 Tim. 4:8) and we should want to do things God calls valuable.

Alas, our sedentary lives and faulty habits stand in the way of fitness. Still, the ideal is within reach. God designed our bodies to respond to exercise. Physical constitutions vary, but many of us can readily jump to 30 pushups and 10 pullups per day. A simple pullup/pushup bar lets us do exercises that strengthen most arm and torso muscles in a few minutes. It’s easy to add exercises for core strength. Sadly, injury, illness, and congenital problems make sports and rigorous exercise impossible for many. Still, most men and women can at least walk so that cardio-vascular health is in reach.

Sports and exercise have been part of my life since my late 20s, when the brute strength of youth started to wane. I’ve slipped at times, but when I get back in shape, I feel whole again. Most of us have more energy, sleep better, and think better when we exercise. Beyond that, most of my peers judge that exercise enhances our endurance even at the desk. And who doesn’t feel more confident knowing he has the stamina to run a mile (right now in street clothes) to get help or the strength to carry someone to safety?

So Scripture may not mandate fitness, but we should regard bodily strength as normal, wise, and good. When professionals sit at desks all day, we can lose contact with our embodied nature. Exercise helps us recover our whole self, so we can heed the call to be strong and courageous.