This post first appeared at The Gospel Coalition.

Adam and Abigail found their first apartment in an older building near downtown, a tight space the couple made comfortable by purchasing some furniture and putting down a big carpet remnant over the hard tile floor. Two years later when their daughter, Penny, came along, the new parents worked hard to childproof the place. But in spite of their best efforts, the rolled-out carpet with frayed edges became a great temptation for their little girl. As a toddler, Penny developed a habit of crawling to the edge of the carpet, unraveling one of the loose strings, and stuffing the threads into her mouth. If her parents didn’t catch her right away, little Penny would fill her mouth so full that she’d begin to choke. 

Adam and Abigail were frightened. What would happen if they didn’t get to Penny in time? The danger of this choking hazard moved the young mom and dad to action: Adam cut the strings off of the borders of the rug, and when their daughter still found a way to unravel the threads, Abigail made a trip to the craft store to purchase fabric glue. Still, the allure of putting the strings in her mouth was too much for Penny. They told her “No” time after time, but Penny would simply look back with a glint in her eye, then move defiantly toward the edge of the carpet.

Finally, Abigail looked at Adam and whispered, “I think we’re going to have to spank her.”  

Why We Need Discipline

Kids aren’t born fully mature, and they aren’t born morally neutral either; Scripture insists that all are born sinners. For these reasons, kids need discipline. Ephesians 6:4 says, “Fathers, do not provoke your children to anger, but bring them up in the discipline and instruction of the Lord.” The Greek word our versions translate as “discipline” (ESV) or “training” (NIV) denotes the idea of giving commands and admonitions, issuing warnings and reproof, and also meting out punishments. The same word is used again in Hebrews 12:4–11 to refer to the pain God sends believers for their growth and sanctification. The author of Hebrews tells us, “No discipline seems pleasant at the time, but painful. Later on, however, it produces a harvest of righteousness and peace for those who have been trained by it.” Verses like this teach us that receiving discipline is a pathway to a good life (Ps. 119:93; Prov. 22:15). Children need to learn that living within the boundaries God has given both protects them and also frees them to experience flourishing (Eph. 6:1–3). 

So, when Penny next moved toward the frayed edges of the carpet, Adam gave her a swat on her bottom. Penny cried, and as he picked up his daughter to comfort her, Adam’s sensitive heart hurt; this was his first use of the rod. Disciplining their daughter was not something Adam and Abigail had looked forward to, but they loved their little girl, and they knew disciplining her was necessary for her safety. Thankfully, Penny took to her parents’ correction quickly. After that first experience of corporal punishment, Penny only repeated her offense once. The pain of a second swat somehow made chewing the carpet less tempting. 

Discipline and the Law’s Three Uses

Biblical discipline isn’t a magic formula that guarantees godly kids, but it does have an important place in each child’s life. Physical correction isn’t always necessary or even the best way to handle discipline, but spanking for young children, and more nuanced consequences for older children, does help shape their outward behavior and guide their hearts.

Ultimately, however, we’re not consistent disciplinarians because our chosen methods are effective, but because this is what God would have us do. Whether or not our kids seem to respond to the consequences, discipline forms their life in accordance with the purposes of his holy law.

And as we learn from Reformation theology, the law has three uses. It is a curb, a mirror, and a guide.

1. The law is a curb.

It restrains evil. Like those metal guardrails on the side of the interstate, the law holds society as a whole back from careening headlong toward chaos and disaster. Just and merciful rules are important both in society at large and also in our families; they guard against prejudice and favoritism, and they protect the vulnerable.

Neither rules nor the rod can change a child’s heart, but they do provide structure, order, and the threat of loving punishment. And this can both restrain a child from disobedience and also protect her from danger as well.

Many simple rules that kids learn—like “look both ways before you cross the street” or “don’t eat the carpet”—are meant for this sole purpose: to protect them from danger and keep them safe. 

2. The law is a mirror.

It shows us our sin against the standard of God’s righteous love. The Bible says learning God’s commands and laws are like drinking milk or learning your ABCs. The law is the most elementary teaching about life in God’s world (Gal. 4:3; Col. 2:20; Heb. 5:11–13). In the law, God demands that we love him with all our hearts and love our neighbor as ourselves (Matt. 22:37–40; Ex. 20:12; Micah 6:8). But though the heart of God’s law is easily summarized, it is not easily kept. When we stand before its perfect standard, we see all our blemishes (Rom. 3:20). The rules and the rod were designed for this purpose. Discipline shows children their sin and guilt not only before us as their parents, but also before a holy God (2 Kings 22; Rom. 7:7–9). 

In Galatians, Paul even describes the law as a disciplinarian—a guardian and manager that brings condemnation on God’s people enslaved by sin until Christ comes to set them free (Gal. 4:15). We need to raise our kids in ways that mimic this dynamic. Rules and discipline highlight the gap between our kids’ sinful hearts and God’s perfection. Spanking is unpleasant, and it teaches our kids that sin is unpleasant. It shows them, in a tangible way, how repulsive sin is. Sin may seem sweet for a minute, but it goes down painfully. 

In this way, consistent discipline can be a tool the Holy Spirit uses both to bring conviction of sin and to make a child’s conscience tender, ready to hear the gospel of grace.

3. The law is a guide.

For converted Christians made alive by the Holy Spirit, the law teaches us our most basic vocation—to love God and love neighbor. Christ was speaking of this third use of the law when he said those who become his disciples must be taught everything he’d commanded (Matt. 28:20).

Like a faithful guide, the moral law teaches Christians how to live and love. We’re free from the law as a system for salvation (Rom. 6:14; 7:4, 6; Gal. 2:15–19), but we’re taught to fulfill Christ’s law in the way we live (1 Cor. 9:21; Gal. 6:2). 

What Discipline Is Not

These three uses of the law not only teach us what discipline is, they also show us what discipline is not. 

When we discipline our children, our goal is not retribution—meting out all their failures deserve. We want our kids to learn the depth of their sin, but we don’t need to “make them pay.” Christ has already taken full punishment on their behalf (Isa. 53:4–5; Rom. 5:8).

Moreover, when we discipline our children, we must remember that the law’s correction is not saving. Only Christ’s death for our sins is. The kindness of God leads us to repentance (Rom. 2:4; cf. Luke 7:47). So, along with gently training, instructing, and disciplining our children, we must include enormous doses of encouragement and forgiveness. 

Keeping the three purposes of the law in mind, as well as these two limitations, helps us to use corrective discipline as it’s designed. If God has begun a work of brokenness in your child’s heart, then the law has done its work. The time for correction is done; now is the time for a hug (and maybe ice cream, too).

And if your children don’t repent, continue being consistent in your discipline, but don’t expect rules or the rod to reach inside your child’s heart and mind to do what only God’s Spirit can. If you’re parenting for heart change, there’s also a time to put down the rules and go to the Lord on your knees. When you do that, you can be more certain that your discipline has come from a place of love.