It takes a brilliant person to distill a complex thing into its simplest form.
Michelangelo carved the Statue of David from a single block of marble, seventeen feet tall, two years of work, perfect detail down to the tendons in the hands and the veins in the arms. Someone once asked how he created something so magnificent. His answer was simple: “I just removed everything that wasn’t David.”
The opposite of that is the person who has a remarkable gift for taking something simple and making it extremely complicated. (Have you ever had someone try to explain the rules of a board game to you? It is one of life’s great sufferings.)
In Jesus’ day, the religious leaders were the second kind. They had taken God’s law and buried the heart of God under layers of interpretation, rules, and tradition. They made something simple complicated.
There’s a story in Matthew 22 where a group of religious leaders ask Jesus, “Out of all the commands and laws, which is the greatest?” That’s like someone asking you who your favourite kid is. You probably have an answer, but you can’t say it out loud, because that’s how you get in trouble. For Jewish people, every part of God’s law was divinely given and binding. So there’s some risk in answering. But Jesus, the brilliant one, distills it:
“Love the Lord your God with all your heart and with all your soul and with all your mind. This is the first and greatest commandment. And the second is like it: ‘Love your neighbour as yourself.’” (Matthew 22:37–39)
That’s it. That’s the main thing. Love God. Love people.
But how? How do you actually love God with all your heart, soul, and mind? How do you keep the main thing the main thing?
The book of Galatians helps here. Paul wrote this letter because the church had drifted away from the main thing. It’s not a warm hug. It’s a wake-up call.
The heart of the book is freedom: “It is for freedom that Christ has set us free” (Galatians 5:1).
The reason Christ set you free is so that you would be free. Freedom isn’t a perk for Christians. It’s the point.
But Paul knows we’re prone to drift away from real freedom into one of two ditches: license and legalism.
He writes, “You, my brothers and sisters, were called to be free. But do not use your freedom to indulge the flesh” (Galatians 5:13). He’s addressing a real temptation: turning God’s forgiveness into permission. We can knowingly, even premeditatively, sin because we whisper to ourselves, Well, God will forgive me anyway. That’s not freedom. Christian freedom isn’t the right to sin. It is the power to walk away from it.
On the other end is legalism, and Paul really digs in here. If license says, “Ignore God’s law, and that’s how you find freedom,” legalism says, “Obey God’s law, and that’s how you earn freedom.” Both miss it. Paul makes it plain: no external rule can change a person's internal reality. Not guilt. Not pressure. Not law. They might modify behaviour. They can’t transform a heart.
Lead-foot drivers, you know what I’m talking about. What are speed limits? They’re suggestions, right? What do you really want? You want to go fast. No amount of speed signs and photo radar is going to change that desire. They might change your behaviour, but they don’t change your nature.
So if Christian freedom isn’t license and isn’t legalism, what is it? Christian freedom is the desire and ability to love the Lord your God with all your heart, soul, and mind. That’s what you actually want, isn’t it? Not divided loyalty. Not halfway devotion. Not a lukewarm faith. You want to be all-in.
So if that is what we want, and Christ set us free precisely for it, why does it feel like a struggle? Why do we hold back?
I think I’m naming a tension you live with every day. There’s a part of you that wants to love God with everything. And there’s another part that fights against it. Both are inside you at the same time. Two of you. The one who wants to love God with all you’ve got and the one who wants to do something else entirely.
In Galatians, Paul names this battle. He calls it the flesh vs the Spirit. And it’s the war Christians wage every day.
Listen to Paul writing about this in Romans. It reads like a journal entry: raw, personal, and messy.
“I do not understand what I do. For what I want to do I do not do, but what I hate I do… For I have the desire to do what is good, but I cannot carry it out. For I do not do the good I want to do, but the evil I do not want to do, this I keep on doing… For in my inner being I delight in God’s law; but I see another law at work in me, waging war against the law of my mind and making me a prisoner of the law of sin at work within me. What a wretched man I am!” (Romans 7:15, 18–24)
For Paul, tension isn’t a strong enough word. He calls it war. And that’s what it is.
If you’re not a Christian, this war won’t fully make sense to you. You can watch coverage of a foreign war on the news, follow the headlines, even understand the history, but you don’t feel the fear or the fatigue the way a soldier on the ground does. So this particular war between flesh and Spirit may not click. But you should know that you’re in a different war, whether you realize it or not — a war against God Himself. Not necessarily full-on hostility, but resistance. The Bible says that apart from Christ, we’re not neutral toward God; in Romans 5, Paul actually uses the word enemies. But that’s not how God sees you. What kind of person dies for His enemies? Christ died, for you. So the war isn’t God resisting you. It’s you resisting Him. War, at its core, is a clash of wills and a fight over who gets to lead. And you can’t win that war by fighting harder. You win by giving in.
When you become a Christian, you stop fighting against God. But you don’t stop fighting altogether. You take up a new battle. It’s not God vs. you anymore. The battle becomes old you vs. new you.
Here’s how this works. When you become a Christian, something staggering happens.
“When you believed, you were marked in him with a seal, the promised Holy Spirit.” (Ephesians 1:13)
To be a Christian is to have God’s Spirit living in you. At the moment of salvation, the Spirit of God took up residence in your life. He breathed His life into yours. And the Bible says it changes everything: “Therefore, if anyone is in Christ, the new creation has come: The old has gone, the new is here!” (2 Corinthians 5:17).
The old has gone. The part of you that resisted God and fought Him, is no longer who you are. You went from rebellion to relationship.
We sometimes miss this, but here’s the proof: the very fact that you want to love God with all your heart, soul, and mind, even if it is a struggle, indicates a fundamental change. You are a new creation. God’s Spirit lives in you. Your nature has changed.
Theologians call that change ontological, a change in essence. Not just behaviour, but nature. You aren’t just acting differently. You are someone new. And that’s why God doesn’t save us with speed signs. He doesn’t save us by adding more external rules. He saves us with Himself, from the inside out. Your desires, your heart, your very nature change.
Before you bowed your knee to Jesus, pleasing God wasn’t on your radar. It wasn’t even in your vocabulary. Now? You want to live for Him. When you read Jesus saying, “Love your enemies,” you don’t scoff. You want to be the kind of person who does that. When He says, “Turn the other cheek,” it somehow makes sense to you. When He says, “Take up your cross and follow me,” you’re drawn in. Where did that come from? Not you. God put His Spirit in you, and that has changed you to your core.
But with the new life comes a new fight. Before Christ, your fight was against God. Now it is old you versus new you: the parts that still resist Him against the part that wants to live for Him.
Paul puts it plainly: “Walk by the Spirit, and you will not gratify the desires of the flesh. For the flesh desires what is contrary to the Spirit, and the Spirit what is contrary to the flesh. They are in conflict with each other, so that you are not to do whatever you want” (Galatians 5:16–17).
When Paul says flesh, he isn’t saying your physical body is the enemy. He means the part of you that still resists God. The old you doesn’t care about the main thing. The new you does.
So the million-dollar question: How does one fight the old self, and better still, how does one win?
Paul’s answer: walk by the Spirit.
If you’re a creative type, you love a phrase like “walk by the Spirit.” It’s evocative, it’s open, it’s poetic. If you’re a left-brain analytical thinker, that phrase can feel uncomfortably abstract.
So let me make it concrete. To walk by the Spirit is to move your life in God’s direction. Think of your life like a compass. Every day, every decision, and every step moves you either toward God or away from Him. Walking by the Spirit doesn’t mean perfection. It means orientation. It means your life is pointed at Jesus, even when the steps are small.
In Greek, the phrase “walk by the Spirit” is in the present tense, active voice, imperative mood. Here’s what that means:
Walking by the Spirit is daily. In the present tense, it is ongoing and continuous. You don’t say to yourself once, “From now on I’m going to walk by the Spirit.” It’s day by day, moment by moment. Am I going to gossip or guard someone’s dignity? Am I going to fire off that text or pause and pray? Am I going to exaggerate or tell the truth?
Walking by the Spirit is deliberate. In the active voice, you are the one walking. Your parents don’t walk by the Spirit for you. Your pastor doesn’t. God Himself doesn’t. We sometimes get confused here. We think that since the Spirit lives in us, we’re supposed to flop on the ground and let God do everything. He won’t. God will not open your Bible and read it for you. God will not call your friend and apologize for you. God will not fill out your TurboTax. He has changed your heart, and He will lead you by His Spirit. But you have to walk.
So who lives the Christian life, the believer or God within the believer? Trick question. When you sin, you don’t say, “That was God’s fault.” It’s you. When you do good, you don’t say, “That was me!” — you know it was His Spirit. The Christian life is 100% Spirit-dependent. Without Him, you wouldn’t even want to love God. But the Christian life is not Spirit-automatic. God leads. You follow.
Walking by the Spirit is demanded. In the imperative mood, it is a command. Walking by the Spirit isn’t optional. It’s how you survive. There are only two ways to walk: by the Spirit or by the flesh. If you’re not walking by the Spirit, you’re walking by the flesh by default. And you don’t want that. If you don’t choose your priorities, your pressures will.
The million-dollar question was, how do I fight the old me? Walk by the Spirit. That’s how we fight and win.
Christians cannot only be known for inner peace. They must also be known for inner warfare. The question isn’t are you in a fight? You know you are. The question is, are you fighting?
Every time you come to church, you fight. Every time you pick up your Bible, you fight. Every time you get on your knees, you fight. Every time you forgive, repent, pray with your kids, choose purity, worship, or share your faith, you fight.
So is there any area of your life where you’ve stopped fighting? Not where you are struggling, but where you have made peace with sin, made peace with the flesh? Maybe with sexual purity. With intimacy with God. With integrity. With a Godly marriage.
You’re not defeated. You’re just disengaged.
Re-engage. Walk by the Spirit. Fight the good fight. At the end of his life, Paul wrote to Timothy, “I have fought the good fight, I have finished the race, I have kept the faith” (2 Timothy 4:7).
There’s a good fight and a bad fight. You’re going to fight regardless. For Christians, the battle is flesh vs. Spirit, old you vs. new you. That’s the good fight.
So fight.