You’ve probably noticed that trying to live a godly life as a Christian can be a struggle. Perhaps it has felt like a spiritual tug-of-war has been going on inside you. And perhaps you’ve wondered, “Is this normal? Do other Christians struggle the way I’m struggling? Or is there something wrong with me?”

These questions remind me of the questions often asked by new parents who are wondering whether something’s wrong with their child because he or she is acting a certain way. They might ask the pediatrician (or perhaps Dr. Google) questions like: My baby cries constantly; is that normal? My baby won’t take a bottle; is that normal? My baby’s always hiccupping; is that normal? My baby poops so much; is that normal?

Usually, the answer is, “Yes. Don’t worry about it. Everything’s fine.”

In the same way, it’s very normal for Christians to struggle with sin. In fact, that’s a good sign that you are a Christian—because, before you became a Christian, you didn’t struggle with sin. You just gave in all the time. You gave yourself over to those sinful desires. But now that you’ve been saved, you’re in a spiritual battle. And yes, it is normal to fight every day in hand-to-hand combat.

In Ephesians 4:22-24, Paul lays out a battle plan for engaging in this hand-to-hand combat. He states that believers should seek “to put off your old self, which belongs to your former manner of life and is corrupt through deceitful desires, and to be renewed in the spirit of your minds, and to put on the new self, created after the likeness of God in true righteousness and holiness.”

So the key to experiencing real transformation is to take off the old and put on the new. However, pay careful attention to verse 23: “to be renewed in the spirit of your minds.”

When you think about it, merely taking off the old and putting on the new is an approach that could easily be recommended by a secular counselor who’s only interested in behavior modification. They may not use all the Christian language we’ve been using, but they’d probably have the same basic approach of stopping old habits and replacing them with new habits. And there are a variety of different practical tricks and tips that they could give you to help you do that and form new habits.

But that’s not real transformation. That’s just modifying external behaviors.

If you want real transformation, you have to dig down deep to the heart, to the mind, to the inward person. And I would suggest that only Christians—with the Bible and the Holy Spirit—have the necessary equipment to do that. The key is the renewal of our minds.

Such renewal brings transformation to the core of our being. Paul makes a similar statement in Romans 12:2. He says, “Do not be conformed to this world, but be transformed by the renewal of your mind.” That’s where Christian change—true change—starts.

Our neighbors recently shared with us about their struggle to get nice grass to grow the past 7 or 8 years. Every year, they would work very hard in their yard to plant grass seed, water the grass seed, and do everything else needed to take care of the grass. And yet, year after year, the grass would always die on them. And it was so frustrating to them because they couldn’t figure out why their grass kept on dying. So finally, this past year, they took a soil sample and sent it off to a state university to get it tested, and they found out that their soil was extremely deficient of lime. All of their efforts to get healthy grass to grow had been futile because there was a lime deficiency in the soil. And until they addressed that deeper issue, they weren’t going to enjoy healthy grass.

In the same way, if we want to experience real transformation, we have to address the deeper issues, the twisted thinking that leads to the ungodly living. That’s why Paul says in verse 23 to be “renewed in the spirit of your minds.”

And the way you experience such renewal in your thinking is to saturate your mind with the truths of the Bible. It’s kind of like marinating meat. You want the flavor of that marinade to sink down into all the pores of the meat so that meat is saturated. That’s what we want to happen to our mind as we marinate our mind in the truth of the Bible.

Furthermore, as we read the Bible, I think we would do well to pay special attention to the truths about (1) who God is and (2) what God has done for us in Christ.

First, study God. Fill your mind with truths about God’s glory and greatness and love and righteousness. You’ve probably heard the old adage, “You are what you eat.” Well, spiritually, I think we could say, “You are what you think.” And if you spend all your time thinking about common things—not even necessarily sinful things, but just the common things of this world—and you only spend a minute or two every once in a while thinking about beauties and glories of God, no wonder you’re not more like Jesus. No wonder you’re not reflecting God’s glory in your life. Look what your mind has been marinating in! It’s been marinating in used car oil from Jiffy Lube. Instead, try marinating your mind in the attributes or characteristics of God.

And the place we see those attributes and characteristics most clearly is in the gospel message about Jesus. That’s the second item to which we should pay special attention. The gospel of Christ is the clearest window we have to who God is. So as you’re reading the Bible, pay careful attention to everything it says about Jesus: the glory he’s possessed from eternity past, the radical way in which he condescended to become a real human being, the life he lived without even a hint of sin, his ministry and message while he was here on earth. And of course: how he endured the agony of the cross to take the punishment for our sins, how he victoriously rose from the grave in resurrection life, and how he ascended into heaven as the King of Kings and the Lord of Lords with every square inch of this universe under his lordship. Think about that. Marinate your mind in that, and your mind will be renewed.

So stop trying to defeat sin simply by gritting your teeth, which—in case you haven’t noticed—doesn’t work that well. Study God and the gospel, and you’ll find that you begin to desire God more than you desire the sin. That’s the secret to getting victory over the sin in your life. Seek God, desire him, and nothing else will be able to compete with the vastly superior pleasures of God himself.

It will be a slow and gradual process, kind of like trench warfare, but over time you’re going to take ground from the Enemy – bit by bit, mile by mile, sometimes inch by inch. But if you do what Paul teaches in Ephesians 4, taking off the old self, being renewed in the spirit of your mind, and putting on the new self, then real transformation will happen—from the inside out.