As we come to the end of John Flavel’s Keeping the Heart, I want to divide this final lesson into four parts. First, I’ll address an unintentional omission from our last lesson. Second, I’ll offer some additional biographical context, which I think will deepen your appreciation for Flavel’s writing. Third, we’ll examine six additional guidelines he provides for keeping your heart throughout every season of life. And finally, I’ll leave you with three comforts for weary and struggling saints.
Closer fellowship with other believers
Let’s begin with the omission. Some of you noticed that I inadvertently skipped one of Flavel’s ten encouragements last time. I missed number nine entirely. If you’ve been taking notes, you might want to turn back and add it now: Closer fellowship with other believers.
Flavel argues that when we keep our hearts—guarding them from sin, not merely restraining outward behavior—we also preserve the unity of Christ’s body. We avoid the selfishness, pride, and carnality that so often fracture our relationships with one another. He writes:
If professing believers would study, watch, and keep their hearts better, all this would be prevented, and the beauty and glory of fellowship would again be restored. We would no longer divide, [dispute], or rashly judge. If our hearts were in tune, our tongues would not jar. How charitable, compassionate, and tender we would be to one another if we were daily humbled under the evil of our own hearts.
The psalmist puts it even more succinctly: “Behold, how good and pleasant it is when brothers dwell in unity!” (Ps 133:1).
But where pride, resentment, or unforgiveness reign in the heart, such unity cannot flourish.
Now, with that settled, let’s turn the page—literally and figuratively—and begin today’s lesson.
A brief biography of John Flavel
Throughout this series, I’ve been learning more about John Flavel’s life. Truth be told, when I started, I didn’t know a great deal about him. I shared some of his story earlier, but I think there’s more you need to hear.
The key thing to understand about Flavel is this: he did not write Keeping the Heart from the comfort of a quiet study, insulated from suffering. There are times when a minister must speak on subjects he has only studied, not lived. For instance, I could teach about persecution, explaining what Scripture says, even offering contemporary examples, but having never endured it myself, my words would inevitably lack a certain weight.
Flavel’s words, however, carry that weight. He knew persecution firsthand. He endured profound personal tragedy and hardship. The seasons he describes in this book are not abstract to him; they are the seasons of his own life. He wrote these words from within the very furnace he describes.
And for me, that realization changes how I read him. It gives his counsel a depth and credibility that only suffering can impart. Somehow, his words take on a whole new meaning.
John Flavel was raised in a godly home. His father, Richard Flavel, was a Puritan minister. You may recall that the Puritans arose within the Church of England. Though the Church of England was Protestant, it retained practices and forms of worship that many believers found too reminiscent of Roman Catholicism. The Puritans sought to “purify” the church further, pursuing a simpler and more biblical faith.
Following in his father’s footsteps, Flavel studied for the ministry at Oxford and was ordained in 1650. He first pastored a small congregation, but in 1656 he made what can only be described as a selfless decision: he left that post to shepherd a larger church in the seaport town of Dartmouth. Although the congregation was larger, the position came with a substantial salary cut. Clearly, his priority was not financial gain but the opportunity to reach more souls with the gospel. His heart was set on leading as many people as possible to Christ.
By all accounts, Flavel’s ministry flourished. Still a young man, his preaching was described as deeply biblical, marked by earnestness and simplicity. He had a gift for making profound theology accessible, often employing vivid, down-to-earth illustrations that resonated with ordinary people.
It was during these early years that he married for the first time. Tragically, we know little about his first wife, not even her name. What we do know is that their marriage was brief. She died only a few years later, leaving Flavel a widower.
Around the time of her death, the Act of Uniformity was passed in England. This law made it illegal to dissent from the Church of England. Ministers were required to conform or be expelled. Flavel, along with his father and some 2,000 other Puritan ministers, refused. In 1662, they were ejected from their pulpits, an event that became known as the Great Ejection. Overnight, Flavel lost his church, his income, and his home.
Yet he remained undeterred. He began meeting secretly with his former congregation—sometimes in homes, sometimes in barns, sometimes in the woods. These gatherings were dangerous. Soldiers patrolled the countryside to break up unlawful assemblies. Flavel was often forced to flee for his life. One account recounts how he disguised himself as a woman to slip past armed guards. On another occasion, he rode his horse into the sea and swam to safety. His story includes moments of real peril and courage.
During this turbulent period, he remarried. But tragedy struck again: his second wife and their newborn child both died during childbirth.
As if these sorrows weren’t enough, Flavel’s parents were arrested for continuing their ministry. Imprisoned in wretched conditions, they both succumbed to the Great Plague of 1665. They died behind bars for their faithfulness to Christ.
It was in these years, marked by grief, danger, and loss, that Flavel began writing Keeping the Heart.
In 1665, another blow came with the Five Mile Act, which forbade ejected ministers from living within five miles of their former parishes. Flavel relocated to the village of Slapton, determined to remain as close to his scattered flock as the law allowed.
I’ve often heard people ask, “How is it that we have so many books and writings from the Puritans?” I don’t have a definitive answer, but I suspect part of it lies here: they were kept from their pulpits. What happens when you silence a zealous, faithful, earnest preacher? He writes. He pours his sermons, his prayers, and his meditations onto the page. And that’s exactly what so many Puritans did. They wrote and wrote and wrote.
After the Five Mile Act forced him into exile, Flavel completed Keeping the Heart. It was published in 1668 under its original title, A Saint Indeed.
Think for a moment about what he writes in that book. Consider this line: “God by such humbling providences may be accomplishing that for which you have long prayed and waited.”
When we know Flavel’s backstory, we see that this is no theoretical musing. He understood “humbling providences” in the rawest sense. He had been hunted and persecuted, narrowly escaping capture on numerous occasions. He had buried two wives and a child. He had lost both parents to plague while they languished in prison for their faith. And yet he could write with unshakable conviction that God might use such trials to fulfill long-awaited prayers.
That is profound trust in God’s purposes.
Briefly, let me tell you how his story ends. In 1672, King Charles II issued a Declaration of Indulgence, temporarily allowing Puritan ministers to return to their churches. Flavel gladly rejoined his flock in Dartmouth. But the reprieve was short-lived. Within a year, the persecution resumed. Nonconformist ministers were hunted and arrested. In Dartmouth, townspeople even burned Flavel in effigy, knowing he still preached in secret.
During these years, Flavel married a third time, only to be widowed again a few years later.
Finally, in 1687, King James II granted freedom of worship. For the first time in 25 years, Flavel could preach openly without fear of persecution. He returned to Dartmouth, where the congregation built a new meetinghouse. He married a fourth time and spent the last four years of his life ministering joyfully and tirelessly to his beloved people.
One evening, while riding alone, Flavel became so overwhelmed with joy in the Lord that he stopped his horse, dismounted, and fell to the ground weeping with gratitude right there by the roadside.
He died in 1691 at the age of 63 while on a preaching trip. He suffered a stroke, and his final recorded words were these: “I know that it will be well with me.”
Flavel endured immense suffering, yet he was right. The Lord granted his deepest desire—to reach as many people as possible with the gospel. And through “humbling providences,” God multiplied his influence far beyond what Flavel could have imagined.
Consider one example: a man once purchased Keeping the Heart with the sole intention of mocking it. But as he read, he was so convicted of his own sin that he returned to the bookseller, bought 100 more copies, and distributed them freely.
Clearly, the Lord used Flavel mightily. Arguably, it was only through those humbling providences that he became so effective in his ministry.
6 guidelines for keeping the heart
With that, let’s turn to the final parts of his book. Next, we come to six additional guidelines for keeping the heart.
1. Live in the Word
Here we encounter one of Flavel’s most memorable lines: “Keep the Word, and the Word will keep you.”
Part of what it means to keep our hearts, as Proverbs 4:23 commands, is learning to set boundaries that help us recognize when our hearts begin to stray. Think of how you train a dog to stay within your yard. You teach him where the property lines are, when he’s gone too far, and how to stay within them. So, how do we train our hearts to do the same?
We need the Word of God for this. As the psalmist says, “Your word is a lamp to my feet and a light to my path” (Ps 119:105). Scripture illuminates the way forward. It shows us where to step and where not to step. It sets the boundaries.
The 1689 Baptist Confession puts it this way: “The whole counsel of God concerning all things necessary for his own glory, man’s salvation, faith, and life, is either expressly set down or necessarily contained in the Holy Scripture.”
The Bible is our ultimate authority. We don’t rely on traditions, novel teachings, or shifting personal feelings. We trust and obey God’s revealed will as communicated through his Word.
But Flavel presses the lesson further. As we’ve seen throughout this book, he has no interest in promoting a superficial or hypocritical religion. Knowing the Bible, even obeying its commands, is not enough if the Word does not penetrate and preserve the heart. He writes, “Just as first receiving the Word regenerates your heart, so keeping the Word within you will preserve your heart.”
James puts it like this: “Of his own will [the Lord] brought us forth by the word of truth” (Jas 1:18). And Peter writes, “You have been born again, not of perishable seed but of imperishable, through the living and abiding word of God” (1Pe 1:23).
The Word was the instrument God used to change our hearts in the first place. It stands to reason that it remains his instrument for preserving them.
Notice Paul’s exhortation in Colossians 3:16: “Let the word of Christ dwell in you richly.” The teachings of Scripture should not be occasional visitors to our minds, coming and going without leaving much trace. They should dwell richly, abundantly, within us. Paul’s language suggests that the Word should feel very much at home in our hearts, saturating our understanding, shaping our affections, guiding our conscience, and informing our memory.
Flavel writes, “Let it dwell richly, or plentifully, in all that it contains (its commands, promises, and warnings) in all that is in you (your understanding, memory, conscience, and affections). Then it will preserve your heart.”
Psalm 119 says, “I have stored up your word in my heart, that I might not sin against you” (Ps 119:11). That’s a strikingly clear proof text for Flavel’s point. If we want to keep our hearts from sinning, we must store God’s Word in them.
This means far more than hearing a sermon or skimming a passage here and there. It means reading Scripture frequently, consistently, and with the deliberate aim of hiding it deep in our hearts. This type of storage requires careful attention and devotion. We’re not racing through our reading plan to tick off boxes. We’re lingering over God’s Word until it lingers in us.
One of the most effective ways to do this, of course, is memorization. What better way to store God’s Word in your heart than to have it written on your mind?
But memorization isn’t enough if we leave those verses untouched for the rest of the day. As we’ll consider in a moment, meditation is essential. After reading, we must carry God’s Word with us, meditating on it and applying it to our lives.
Flavel writes:
The slipperiness of our hearts with respect to the Word is the cause of so many slips in our lives. Conscience cannot be urged or awed with forgotten truths; but keep them in the heart, and they will keep both heart and life upright.
He then quotes Psalm 37:31: “The law of his God is in his heart; his steps do not slip.” And he adds:
Or, if he does slip, the Word will recover the straying heart again. ‘And Peter remembered the saying of Jesus … And he went out and wept bitterly’ (Matt 26:75). We never lose our hearts until they have first lost the efficacious and powerful impression of the Word.
2. Question your heart
The prophet Jeremiah warns, “The heart is deceitful above all things, and desperately sick; who can understand it?” (Jer 17:9).
I mentioned this in our last lesson, but Flavel strongly encourages us to examine our hearts daily, especially at the close of each day. He would have us speak directly to our hearts, even interrogate them. He offers this searching example:
Oh, my heart! Where have you been today? Where have your thoughts wandered? What account can you give of them? Oh, disobedient heart, vain heart, could you not abide by the fountain of delights? Is there better entertainment with the creature than with God?
This is no small challenge. We have hearts that are not only prone to wander but are deceitful and desperately sick. Yet this is the very thing we’re called to guard and keep.
As the hymnwriter pleads:
Let that grace now, like a fetter,
bind my wandering heart to thee.
Prone to wander, Lord, I feel it,
prone to leave the God I love;
here’s my heart, O take and seal it;
seal it for thy courts above.
Flavel urges us not to let a single day pass without a deep and honest heart-examination. Outwardly, we may have done all the “right” things—dutiful, disciplined, and even admired by others. But he challenges us to look deeper. Where has your heart truly been?
Remember his earlier warnings: the heart is the fountain of all we do. We want to know whether our affections have strayed, whether secret pride, resentment, or worldliness has taken root.
Flavel writes:
The more often our hearts meet with rebukes and checks for wandering, the less they will wander. If every vain thought were retracted with a sigh, and if every excursion of the heart from God were met with a severe check, we would not dare so boldly and frequently to digress and step aside. The actions that are committed with reluctance are not committed with frequency.
3. Make room for God
Perhaps our greatest challenge in keeping the heart is the sheer busyness and distraction of daily life. We rush through our days with a thousand tasks to complete and a thousand thoughts vying for our attention, leaving little time or inclination for God and heavenly things.
The apostle Paul exhorts us:
If then you have been raised with Christ, seek the things that are above, where Christ is, seated at the right hand of God. Set your minds on things that are above, not on things that are on earth. For you have died, and your life is hidden with Christ in God. When Christ, who is your life, appears, then you also will appear with him in glory. (Colossians 3:1–4)
Or consider his words in 1 Corinthians 7:
The appointed time has grown very short. From now on, let those who have wives live as though they had none, and those who mourn as though they were not mourning, and those who rejoice as though they were not rejoicing, and those who buy as though they had no goods, and those who deal with the world as though they had no dealings with it. For the present form of this world is passing away. (1 Corinthians 7:29–31)
Paul is not advocating withdrawal from the world or neglect of our responsibilities. He’s calling for a reorientation of heart—a conscious focus on what is eternal rather than what is fleeting. This life, and all its concerns, will soon pass.
But if we’re honest, our hearts are naturally prone to the opposite. We become consumed with what is temporary, tethered to what is earthly. Flavel warns, “Take heed, Christian, lest your shop steal away your heart from your closet. God never intended earthly employments for a stop but rather for a step to heavenly ones.”
Flavel continues with a vivid illustration: “If your ship is overladen, you must cast some cargo overboard. More business than you can well manage is like more meat than you can well digest: it will quickly make you sick.”
If we are serious about keeping our hearts from sin, we must be equally serious about reorganizing and reprioritizing our lives. The Lord—his kingdom, his Word, his presence—must come first.
If something must give way, let it not be Christ.
4. Watch for warning signs
When Proverbs 4:23 exhorts us to “Keep your heart with all vigilance”, it evokes the image of a sentry posted on a city’s walls. His job is to watch carefully for any approaching enemies and sound the alarm to those within. In the same way, we must be watchful over our hearts. Subtle dangers can creep in—little thoughts, habits, and affections that, left unchecked, can do great spiritual harm.
Flavel warns:
If you mean to keep your heart, you must carefully observe its first backslidings from God and stop it there. A man who wants his house to be in good repair must stop up every crack as soon as it is discovered, and he who would keep his heart must not let a vain thought be long neglected. Apostasy, the serpent of the heart, is best killed as an egg of a small backsliding.
He continues with a series of vivid illustrations:
Oh, if many poor, decayed Christians had looked to their hearts in time, they would never have ended up in the sad condition they currently find themselves in. We may say of heart-neglect as the apostle does of vain babblings—that ‘it will lead people into more and more ungodliness’ (2 Tim 2:16). Little sins neglected will quickly become great, uncontrollable ones. The greatest crocodile once lay in an egg, and the greatest oak was once only an acorn. The lighting of a small amount of gunpowder may blow up all by leading to a greater quantity. People think very little about what a proud, vain, lustful, or worldly thought may grow to be. Behold how great a matter is kindled by a small fire.
This is classic Flavel, using simple, striking images to drive his point home.
The apostle Paul gives a similar warning: “Do you not know that a little leaven leavens the whole lump? Cleanse out the old leaven that you may be a new lump.” (1Co 5:6–7)
Even the smallest sins or signs of backsliding must not be ignored. Stop them early before they gain influence, before they harden into habits, before they corrupt the heart.
5. Stay close to God
At first glance, this point might seem like a repetition of number three, “Make room for God,” but there’s an important distinction. Here, the focus isn’t merely on turning away from distractions or clearing space in our lives. It’s about what we’re turning toward.
We’re not just emptying our hearts of lesser things; we’re filling them with the greatest thing—God himself.
Flavel puts it beautifully:
The heart is a hungry and restless thing; it will have something to feed upon. If it enjoys nothing from God, it will hunt for something among the creation, and there it often loses itself as well as its purpose.
This is the danger of mere detachment. If we remove distractions but do not actively pursue God, our hearts will inevitably seek something else to satisfy them, and they will not stop until they find it, even if what they find cannot truly satisfy.
So yes, make room for God by laying aside lesser things. But don’t stop there. Seek him. Draw near to him. Fill that void with his presence, his Word, his worship, his fellowship. Only then will your heart find rest.
6. Meditate
I told you we’d return to this point. Flavel writes:
Habituate your heart to spiritual meditations if you would have it freed from those burdensome diversions. By this means, you will gain an ability and dexterity in heart-work. It is a pity those smaller portions of our time between solemn duties should lie in our hands and be rendered useless to us. Oh, learn to save and be good caretakers of your thoughts.
What occupies your mind in the in-between moments? Flavel assumes his readers are faithful in their “solemn duties,” gathering with the church, reading the Word, and praying. But what about the rest of the day? When the worship service ends, when the Bible is closed, when the prayer is finished, what fills your thoughts then?
For most of us, it’s all too easy to shift immediately to earthly concerns. We leave church on Sunday and begin running through Monday’s to-do list. We close our Bibles and dive straight into emails, errands, and endless notifications. We scroll through newsfeeds, absorbing the latest scandal or disaster.
But Flavel urges us to redeem those ordinary moments—to train our minds to return again and again to Christ. Imagine how much richer our spiritual lives would be if we used even the briefest pauses in the day to meditate on the gospel, to reflect on the sermon we heard, or to pray through a verse of Scripture.
Paul puts it this way in Philippians 4:
Finally, brothers, whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is lovely, whatever is commendable, if there is any excellence, if there is anything worthy of praise, think about these things. What you have learned and received and heard and seen in me—practice these things, and the God of peace will be with you. (Philippians 4:8–9)
Set your mind on what is good, lasting, and Godward, not on every trivial distraction the world throws at you.
Flavel even quotes his contemporary Robert Boyle, the chemist and devoted Christian, who offered this striking image of time:
Although grains of sand and ashes are apart and uselessly small so as to be liable to be scattered and blown away, yet the skillful craftsman, by a vehement fire, brings many of these together to afford him that noble substance of glass.
Think of each grain of sand in an hourglass as a moment of your life. A single grain may seem small, insignificant, and easily wasted. But gathered together, and sanctified by the “vehement fire” of meditation, they can form something of lasting beauty and worth.
As Paul exhorts in Ephesians 5, “Look carefully then how you walk, not as unwise but as wise, making the best use of the time, because the days are evil.” (Eph 5:15–16)
Every moment is an opportunity to do something of eternal value. Don’t waste them on trivial things when you could, at the very least, set your mind on spiritual, heavenly realities.
Let’s turn to three comforts for struggling saints.
3 comforts for struggling saints
Even as genuine believers, when we are faithfully practicing this “heart work,” we still often feel the weight of our own weakness. We still struggle to keep our hearts from wandering. Where then do we find comfort?
Consider these three truths.
1. Your heart matters more than your abilities
One of the most common mistakes we make in self-assessment is placing too much weight on our accomplishments. We measure our worth by how much we’ve done for Christ, or worse, by how we compare to others. Perhaps we feel our gifts are too small to be of any use. Perhaps we think we haven’t achieved enough in our service.
But listen to Flavel’s wise counsel:
It will add more to my comfort to spend one solitary hour in the morning before the Lord over heart corruption than many hours in a seemingly zealous, but really dead, performance of common duties with the greatest acclaim and richest embellishments of abilities and gifts.
In other words, Flavel would rather be the tax collector in the temple, crying, “God, be merciful to me, a sinner!” than the Pharisee boasting of his righteous deeds (Lk 18:13). He would rather wrestle honestly with his heart before God than ignore his inward struggles while carrying on with an outward show of religion.
So if you’re struggling with your heart, then struggle. Turn to the Lord for help, yes, but don’t despise the battle itself. As long as you are fighting to keep your heart, you are in a good place.
2. God is working for your good
If God is allowing you to walk through heart struggles, trust this: he intends it for your good. Flavel writes, and it’s worth quoting him at length here:
Pensive soul, let this comfort you: God is working for your good, even by these occasions of your sad complaints. For through these, he helps you see what your heart is and was by nature, and therein to acknowledge how much you owe to free grace! He leaves you under these exercises of the Spirit that you may lie as with your face upon the ground, marveling that the Lord of glory should ever have taken such a toad, so vile a creature, into his bosom. Your base heart, if good for nothing else, yet serves to commend and bring out the unsearchable riches of free grace.
This keeps you from continually resting—even glancing—upon your own righteousness or excellence. The corruption of your heart, working even in your duties, makes you sense that ‘the bed is too short and the covering too narrow.’ Were it not for those meditations on the dullness and distractions of your heart in spiritual duties, how easily you would fall in love with and admire your own performances! For if even with these humbling thoughts you still wrestle with pride, how much more if they were lacking?
And lastly, this tends to make you more compassionate and tender toward others. Perhaps you would feel little pity for the soul-troubles of others if you had less experience of your own.
Every word of this is true. If you belong to Christ, then even your deepest struggles, even those sad, weary sighs of a restless heart, are being used by God as tools of grace, shaping you for your eternal good.
3. Complete rest is near
It won’t be like this forever.
Paul reminds us, “The present form of this world is passing away” (1Co 7:31). Isn’t it true that every burden feels lighter when you know it’s only temporary?
But for God’s redeemed people, the promise is even greater. This isn’t merely an end to struggle; it’s the beginning of a far surpassing life, free of every struggle. No more warring with your flesh. No more wandering of the heart. No more sin. No more distractions. No more tears. There will only be complete, unbroken rest.
“Fear not,” Moses said, “stand firm, and see the salvation of the Lord” (Ex 14:13). Don’t give up. Don’t lose heart. Don’t be afraid.
It won’t be like this forever.
Paul cried out, “Who will deliver me from this body of death?” (Ro 7:24). And his answer came quickly: “Thanks be to God through Jesus Christ our Lord!” (Ro 7:25).
Salvation is coming. Deliverance is certain. And so, along with John, we cry, “Come, Lord Jesus!” (Rev 22:20). Come quickly.