Everyone likes Charlie* at church. He’s a bubbly guy, all kinds of fun, and always has something helpful to share from the Bible. But those close to him know he has serious anger issues. If you disagree with him, he’ll tear you apart. And Charlie knows it’s a problem. He’s tried counselling, he’s tried anger management. But there’s something deeper that counting to 10 just can’t fix.

Jenny* first came across pornography by accident while searching online. Before she knew it, she was hooked. Jenny’s parents, her friends see her as the good Christian girl, but secretly she’s losing sleep, she can’t push pause. Some weeks it’d be like a yo-yo – she’d forced herself to keep away from it, only to bounce back, binge and break down with regret. Many times she’s tried to stop, but she feels powerless. Her desires seem too strong.

I’ve changed names and details for privacy, but their stories are too familiar, aren’t they? And underlying each of our stories, our own struggles with change is this: too often, we’re trying to deal with sin by our own efforts. Obedience based on our own efforts. Sadly, our language in church often doesn’t help. Too often we say to people you’re saved by grace. It’s all Jesus. But then we say: you keep being Christians through hard work, discipline, do’s and don’ts. We’ve adopted this mindset that the gospel is for new Christians. But after that it’s all up to us.

Ephesians 4:20-24 paints a different picture though:

That, however, is not the way you learned Christ! — assuming that you have heard about Him and were taught in Him, as the truth is in Jesus, 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.

Verse 20 literally says “that is not how you learned Christ”: what you learned about Him, what you were taught in Him (v20-21). In other words, Paul is asking his readers to make a mind shift and deal with sin starting with the gospel: who you are in Christ. He doesn’t start with do’s and don’ts, rules and regulations (the commands only pile in from verse 25 onwards). He starts with Jesus. He’s saying: “You know that Jesus lived, died and rose again for you, don’t you? So live like it!”

And the picture Paul uses from v22-24 is a change of clothing. Put off the old self – it’s corrupt. Instead, if you really know Jesus, with your renewed mind, put on your new self that you received from Him!

Trying to fight sin without the gospel is like an insect that won’t shed its old skin. Or reading without glasses. Or heading into battle in your pyjamas. Or showing up to your wedding without your dress or suit. You’re mad if you try and fight sin without the power of the gospel. The call to follow Jesus is not just “do this / don’t do this”, but “live out your new self”. “Walk worthy of your calling” (4:1).  Live out who you are.

That means when people ask me “I’m struggling with ____ or ____”, it’s not hard to guess what I’ll mention at some point: the gospel. Sure, I’ll suggest some ways to sow to the Spirit, strategies to help support repentance and faith. But it’s never in place of remembering Jesus Christ died for you, and living as if it’s true. The gospel is for Christians too.

That’s because sheer willpower is never a long-lasting strategy to fight sin. When you fail, you are crushed. But worse, when you succeeed, the glory doesn’t go to God, because you’ll just be proud of your own amazing strength. Then you’ve just swapped your old sin with a new one, pride. It’s far better to deal with sin with gospel glasses. To fight the devil’s schemes with Jesus’s armour. God doesn’t want a community that relies on their own willpower to hold their lives together. He wants a community of grace that fights sin with the power of the gospel.

In Charlie, there’s a growing delight with God. He still feels angry. But he’s learning to trust God’s in control, and his anger reflects a desire to be in control. So he repents and looks to Jesus to rule His emotions.

In Jenny, the sin and temptation to sin has mostly left her. There are still some falls, but there are many, many victories. She’s learning to find intimacy and closeness with Jesus, and that is lessening her desire to look for it elsewhere.

And in Jesus, we too have everything we need to give up futile, selfish ways of living. To be renewed in our minds, and clothed in God’s likeness: righteous, set apart, ready to live for Him.

(This post is adapted from a sermon I preached on Ephesians 4:17-24. You can check it out below or on  SpotifyApple podcasts  etc.)