This excerpt is a transcript of a sermon by Dr. Michael Reeves entitled “Getting Your Heart Right,” based on Matthew 15:1-28:

… the Pharisees could not understand the idea of the need for a new heart.

Well, that’s all a long time ago, but people haven’t changed.

And that enslavement to that view of reality, that failure, that blindness to the human condition, to the human heart, has just carried on.

And I’m going to give you an example of this from much closer to our day. I’m going to read you from the diary of an 18th-century man, Dr. Samuel Johnson, who first wrote the dictionary of the English language. A literary giant, enslaved man.

And I want to get inside his head and read you a few extracts from his journal. And you’ll just get inside his head.

This is very similar to what we’ve seen in the Pharisees.

Here we go.

September the 18th, 1738: “Oh Lord, enable me by your grace… enable me by your grace to redeem the time which I’ve spent in sloth, vanity, and wickedness. Enable me to lead a new life in your faith, fear, and love. And finally, enable me to obtain everlasting life.”

Nineteen years later, 1757: “Almighty God, enable me from this instant to amend my life that I may not lose the things eternal.”

Two years later, 1759: “Enable me to shake off idleness and sloth.”

Two years later, 1761: “I have resolved, till I am afraid to resolve again. Yet, hoping in God, I steadfastly purpose to lead a new life.”

Three years later, 1764: “I have made no reformation. I have lived totally useless, more sensual in thoughts, more addicted to wine and meat. Grant me, oh God, to amend my life… my purpose from this time to avoid idleness, to rise early, to read the scriptures.”

A few months later: “I’ve now spent 55 years in resolving. Oh God, grant me to resolve aright and to keep my resolutions. I resolve to rise early, not later than six, if I can.”

1765: “I purpose to rise at 8 because though I shall not rise early, it will be much earlier than I now rise, for I often lie until two.”

1775, ten years later: “When I look back upon resolutions of improvement which year after year have been made and broken, why do I try to resolve again? I try because reformation is necessary. I try in hope of the help of God.”

Oh dear. Isn’t it tragic? Isn’t it familiar?

It’s a life of the flesh, of fleshly pleasure, and then fleshly attempts to make himself a new man. It’s all self-effort, with prayers chucked up, asking God to chip in and help him do what he needs to do.

You can hear it here, and he’s even more explicit elsewhere. Johnson went through life ground down with guilt. He just didn’t realize his greatest problem.

He refused to accept the free pardon and welcome of God.

And so he tried to deal with his guilt by self-improvement.

And whatever your theology teaches, isn’t it easy to think, “I don’t have a big problem with sin. I can sort myself out. I resolve to do better. I can do better. And I will do better.”

And that is one of the clearest indicators of a Pharisaical blindness to the depth of sin. The sense that sin is just a behavior problem we can sort out with a bit more effort, with a bit of work by the flesh.

Possibly a tell here would be – have you ever been in this situation? I think it’s so easy for us today in our culture of self-affirmation to believe, “I’m not a deep sinner.”

And even if my theology tells me that we are all – we’ve all fallen short of the glory of God—it’s easy to forget that.

And I think a good tell on that is, have you ever been in a situation where, I don’t know, maybe it’s you’re late for something? You’re stuck in traffic. You’re stressed, you’re anxious. And then someone does something to really annoy you, and out of your mouth come these words. Or if you’re so good you managed to keep your mouth shut, but into your head come all these vicious thoughts. And sometimes they’re so vicious you think, “Whoa, where did that come from? ‘Cause I’m lovely. Where did that come from?”

You’ve forgotten the sewer of sin that bubbles up in all of us.

So I must ask you, dear friends, how much of a sinner do you think you are? How blind are you to the depth of your sin?

Because if you don’t see yourself as a great sinner, what has Christ got to offer you? Christ will never be a great Savior to you. You’ll never love him much unless you see how much he does for you.

So if you think of yourself as a pretty good person, you’ll never really know the joy of treasuring an all-sufficient Savior. You’re trapping yourself in self-identity rather than knowing the joy, the liberation of forgiveness.

And I say this however long you’ve been walking with Christ.

My mentor when I was a very young man, I pastored with him. He was on church staff with me. He was maybe the most godly man I knew. Some of you may have heard of him. He was a great preacher. His name was John Stott. And he was the most wonderfully humble, godly man.

And I remember once seeing him, coming in, he was in private, didn’t know anyone was going to see him. And he was on his knees in tears at his own sin.

And I remember thinking, I was young, I was thinking, “I’m not aware that there’s any sin left in this guy.” Here he is in tears at his own sin.

Because when the Spirit works in your heart, he is a Spirit who’s grieved by sin and he makes you ever more sensitive to sin.

And so those who’ve been walking with Christ a long time, they will find they feel ever more sinful, though actually the Spirit makes them look ever more glorious. They’re ever more sensitive to their sin.

So friend, are you sensitive to your sin? If you’re not, you’re sharing the Pharisees’ blindness, not the Spirit’s sensitivity.

God is so much more thorough than us. Where we would seek to change by putting a thin layer of paint on ourselves and painting ourselves neat and clean, God deals with us all the way down in the foundations of our hearts.

And this is his great promise of the new covenant—to give us new hearts of flesh, transforming not just the symptoms of our behavior but transforming the very desires that drive our actions.

Because the essence of our problem is, while we were made to love the Lord our God, we were created as lovers. And even when we sinned in the fall, we remained lovers. To be human is to love.

But our loves turned. And from turning from being lovers of God—as Paul says it—we became lovers of self, lovers of money, lovers of pleasure rather than lovers of God. That’s been our problem in sin. We still love, but we’ve turned to love the wrong thing. And that’s our real problem.

And we need our hearts turned to love aright. We don’t just need our behavior corrected. We need our very desires turned back to the Lord our God so that we love, adore, cherish him just as once we cherished sin.

Jesus prayed, “Sanctify them in the truth. Your word is truth” (John 17:17). That prayer is not a mere wish but a certainty. Every request of the Son is perfectly aligned with the Father’s will, and every prayer of the Son is answered. He Himself declared, “Father, I thank You that You always hear Me” (John 11:42). His intercession is never denied, never delayed, never ineffective. When Jesus prays for His people, it is as good as done. If you are in Christ, your sanctification is not left hanging in the balance, dependent on your strength alone. It is secured by the perfect petition of the perfect High Priest. Holiness, then, is not an optional add-on. It is God’s unbreakable purpose for you, and He will bring it to completion.

The word sanctify comes from hagiazo, meaning to set apart, to consecrate, to make holy. In Scripture, ordinary things became holy when God set them aside for His service, such as the vessels in the temple. If that was true of bowls and lampstands, how much more is it true of blood-bought people. “You are not your own, for you were bought with a price” (1 Corinthians 6:19–20). Holiness is not mere rule-keeping. It is belonging to God for God, separation from sin and dedication to the Lord. Those vessels, once consecrated, could not be taken home by a priest for a private meal. They belonged exclusively to God’s house, set apart for His service, and to be used only when and how He commanded. That picture helps us grasp what it means to be sanctified: we are not common any longer, not available for just any use, but kept for the Lord.

Positional Sanctification

At conversion, God decisively sets us apart in Christ. This is a change of status and realm. Paul can tell a very messy church, “You were washed, you were sanctified, you were justified” (1 Corinthians 6:11). He even addresses them as “those sanctified in Christ Jesus, called to be saints” (1 Corinthians 1:2). Every Christian is a saint in this sense, not an elite few, but all who call upon the name of the Lord. This aspect is done, completed, and entirely God’s act. It gives us a new identity and standing before Him. And because it rests on Christ’s finished work, it cannot be undone. When shame whispers, “You are what you did,” positional sanctification answers, “No, I am who I am in Christ.”

Progressive Sanctification

This is the daily, lifelong work of the Spirit making us more like Jesus in thought, word, and deed. It is what Jesus prayed for in John 17:17. God uses a holy instrument, His holy Word, to produce holy people. Like produces like. “All Scripture is breathed out by God and profitable… for training in righteousness” so that we are “equipped for every good work” (2 Timothy 3:16–17). Teaching shows the path, reproof shows where we left it, correction brings us back, and training helps us stay on it. Growth is not a straight line upward but often three steps forward, two steps back. Bear in mind, struggle with sin is itself evidence of life, for before conversion we made peace with sin, but after conversion we make war. Yet we must be clear: in this world we never quite reach perfection in holiness. Progressive sanctification is real and observable, but it is always partial until the day of glorification.

And here is the certainty: the Spirit never abandons His work. Paul prayed, “May the God of peace Himself sanctify you completely” (1 Thessalonians 5:23), and then immediately added, “He who calls you is faithful; He will surely do it” (v. 24). The God who began the good work will not leave it half-finished. As Paul writes in Philippians 1:6, “He who began a good work in you will bring it to completion at the day of Jesus Christ.” He takes personal responsibility for your growth in holiness. Theologians have described this beautifully. Berkhof called it “a gracious, continuous work that delivers from the pollution of sin, renews the whole nature, and enables good works.” Hodge said sanctification is both definitive and progressive: a decisive break with sin at conversion and an ongoing renewal. Calvin insisted that Christ justifies no one whom He does not also sanctify. Justification and sanctification are distinct but never divided.

The Spirit works through the Word, prayer, the ordinances, and the fellowship of the church. Growth in holiness is a community project, not a solo endeavor, and it is guaranteed by the faithful hand of God. Central to this is the corporate gathering of the church on the Lord’s Day, where the Word is preached, the sacraments are observed, and the people of God worship together. The Lord Himself calls His people to gather in this way, and we are to obey His summons, knowing it is always for our good. This weekly rhythm of assembling is not optional but vital, for it is one of the chief ways Christ nourishes and sanctifies His bride.

Perfected Sanctification

One day the process will be complete. We will be presented “without spot or wrinkle” (Ephesians 5:27). “He will establish your hearts blameless in holiness” at the coming of Christ (1 Thessalonians 3:13). This is glorification, when there will be no more sin and no more inward war, only full conformity to Christ. For the believer who dies before Christ returns, glorification occurs at death, when the soul is made perfectly holy and enters the immediate presence of the Lord. For those alive at His return, glorification will happen in a moment, as our bodies are transformed and we are caught up to be with Him forever (1 Corinthians 15:51–53; 1 Thessalonians 4:16–17). So certain it is that glorification will occur for the true child of God, Paul writes of it in the past tense: “those whom He justified He also glorified” (Romans 8:30). In other words, the matter is already settled in God’s eternal purpose. Every struggling saint will be glorified. Nothing can derail God’s plan, not Satan, not the world, not even the weakness of our own flesh. Not in an ultimate sense anyway. We aim at holiness now with all our might, but we rest in the assurance that God Himself will finish the work.

These truths protect us from confusion. Sanctification is not the basis of salvation. We are saved by grace alone, through faith alone, in Christ alone. Yet it is not optional, for “without holiness no one will see the Lord” (Hebrews 12:14). Fruit does not save, but living trees bear fruit. It is also not passive. The Christian life is not “let go and let God.” Scripture calls us to “work out” what God “works in” (Philippians 2:12–13). We strive, but God supplies. We labor, but God empowers. And because His power undergirds our striving, the outcome is never in doubt.

Think of a surgeon’s scalpel, sterilized and placed in skilled hands. By itself, it does nothing. In the surgeon’s hands, it becomes an instrument of healing. The Spirit is the divine Surgeon. The Word is His pure instrument. The Spirit takes the Word and cuts away what does not belong, not to harm but to heal, until the likeness of Christ emerges more clearly.

Holiness requires balance. Some fall into legalism, defining holiness only by what they do not do. Others abuse grace as a license to ignore God’s commands. True holiness is both putting off the old and putting on the new. It is separation from sin and consecration to God. It is not isolation either. We grow together in the church through worship, preaching, fellowship, and discipline. Nor is it despair. Positional sanctification reminds us that we are already set apart. Progressive sanctification assures us that God is presently at work within us. Perfected sanctification guarantees that one day we will be made complete. In every stage, certainty rests not on us but on Christ.

What does growth look like in practice? It means daily intake of the Word, praying that the Spirit would make it fruitful. It means continual repentance, keeping short accounts with God. It means walking in fellowship with the church and making use of the means of grace. It means guarding our inputs, since what we behold shapes what we become. And it means serving others, for holiness grows as we give ourselves away. As Luther put it, “God doesn’t need your good works. Your neighbor does.”

At the heart of it all is Christ. Sanctification begins, continues, and ends with Him. He is the One who sets us apart, the One who by His Word and Spirit is making us new, and the One who will present us faultless with great joy. The gospel not only pardons, it purifies. The grace that declares us righteous begins to make us righteous until the day when faith becomes sight. We have been sanctified in Christ. We are being sanctified by the Spirit through the Word. And we will be sanctified completely at His coming. And because Jesus prayed for it, it is certain.