The Marrow of Modern Divinity

The following is an introduction of a reprinting of The Marrow of Modern Divinity.


The Marrow of Modern Divinity
Christian Focus Publications
October 2009

Thomas Boston is one of my favorite authors. Through his sermons, memoirs, and other writings, the prolific theologian and humble pastor of a small rural church in the Scottish border country has become one of the pastors of my soul.

I admire Boston for his spiritual devotion--what Boston himself would have termed "a heart exercised unto godliness." I admire him for his dedication to his calling as a good shepherd. Riding on horseback, he ranged the more than one hundred square miles of his parish to visit each family or individually twice annually for spiritual conference and catechetical instruction. I also admire Thomas Boston for his perseverance. Despite struggling with depression and suffering from chronic physical weakness, he never missed a single Sunday in the pulpit during the course of more than three decades of pastoral ministry. True to form, his final sermons were preached from his deathbed, with the members of his congregation gathered outside the window of the manse. And so, like Jonathan Edwards, I consider Thomas Boston "a truly great divine." 

Yet when Edwards said this, he was not thinking of Boston's work as a pastor, primarily, but of his international influence as a biblical and systematic theologian. Though he served his whole ministry in an obscure parish, Thomas Boston became the most frequently published Scottish author of the eighteenth-century. His books were widely recommended during the Great Awakening in England and America. We know from contemporary accounts that in addition to helping people grow in the Christian faith, these books were instrumental in leading people to Christ--everyone from slaveholders to their slaves.

Like most prolific writers, Thomas Boston was also a prodigious reader. As a man of limited means, his personal library was small--little more than a single shelf of books. Yet he read whatever he could find, and in his Memoirs he lovingly describes new theological books arriving by post.

Boston's favorite book was The Marrow of Modern Divinity, which he discovered early on in his ministry. He spied the book one day in the cottage of a parishioner, who was only too happy to share it with the book-starved pastor. Much later Boston produced his own edition, complete with detailed theological notes. Publishing this edition was a labor of love, because the dialogues he read in The Marrow of Modern Divinity saved Boston's ministry by teaching him "the gospel of free grace." 

The story of The Marrow of Modern Divinity-of its original publication and later influence on the Church of Scotland - is more thoroughly told in the essay that follows, by the church historian William VanDoodewaard. My purpose in this introduction is to answer to a simple question: Why is this old theological book still good and useful to read today?

Perhaps the best way to begin to answer this question is by mentioning two equal but opposite errors that have plagued the church since the days of the New Testament. On the one hand, some congregations tend to be overly legalistic.  They have a performance-based approach to the Christian life, in which Christianity is reduced to a list of rules. A good Christian is someone who does certain things and avoids doing certain other things. The only way to gain favor with God is by leading a good life. Somehow churches like this never manage to outgrow their "inner Pharisee."

Yet there is an equal error in the opposite direction, the sin of lawlessness, or what theologians like Thomas Boston would call "antinomianism" (which simply means to be "against the law"). Churches like this tend to be overly permissive. They take the question that the apostle Paul asked in Romans 6:1 ("Are we to continue in sin that grace may abound?), and answer in the affirmative rather than the negative. They use their Christian liberty as an excuse for license. They may even use the grace of God to legitimize bad behavior.

Both legalism and antinomianism are perennial dangers for the church and for individual Christians. When we begin to think of the Christian life primarily as a list of "dos" and "don'ts," we are under the sway of legalism. When we begin to think that it is okay for us to go ahead and sin, because God will forgive us anyway, we are feeling the temptation of antinomianism. 

The Marrow of Modern Divinity proclaims a gospel that can rescue us from both of these dangers. Filled with quotations from the great reformer Martin Luther and from the worthy Puritans, The Marrow emphasizes biblical, evangelical doctrines such as the sovereignty of God in the covenant of grace, the free offer of the gospel, assurance in Christ as the essence of faith, and sanctification by grace rather than by the law. Thomas Boston loved these grace-filled doctrines and discovered that they strengthened his hold on the precious gospel that he lived and preached. He also perceived, correctly, that these doctrines were necessary to preserve Calvinism from degenerating into either legalism or antinomianism.

Boston was inspired by The Marrow's description of what God has done in giving us the gospel of his Son. To quote from "Evangelist," who is the book's normative theologian: "I beseech you, consider, that God the Father, as he is in his Son Jesus Christ, moved with nothing but with his free love to mankind lost, hath made a deed of gift and grant unto them all, that whosoever of them all shall believe in this his Son, shall not perish, but have eternal life."

Many of Boston's contemporaries objected to the language of "deed of gift and grant" on the grounds that salvation was only for the elect. To describe the gospel as a gift or grant for unbelievers, they said, amounted to universalism. Yet Boston understood The Marrow's "deed of gift and grant" as an open offer of salvation, which needed to be received by faith. To call the gospel a "deed of gift and grant," therefore, was fully in keeping with the Bible's own generous and indiscriminate invitations to salvation.

Boston loved to quote the opening verses of Isaiah 55, which offered water without money and bread without price to hungry, thirsty sinners.  He also loved to quote John 3:16, which extended the offer of eternal life to the whole world. "This is the good old way of discovering to sinners their warrant to believe in Christ," he said, "and it doth indeed bear the sufficiency of the sacrifice of Christ for all, and that Christ crucified is the ordinance of God for salvation unto all mankind, in the use-making of which only can they be saved; but not an universal atonement or redemption." Stated more simply, the death that Jesus died on the cross is sufficient to atone for the sins of anyone who comes to him in repentance and faith. This does not mean that everyone will be saved; people still have to make use of the cross by trusting in Jesus. But it does mean that salvation through the cross really and truly can be offered to everyone.

This free offer of the gospel is liberating for ministry. For Boston, it meant that as a preacher he never needed to be restrained in giving people the gospel. Even the most hardened sinners and most improbable candidates for salvation could be called to faith and told that Christ was available to them. As The Marrow said, in a quotation from the famous Puritan preacher John Preston: "Jesus Christ himself said unto his disciples, Mark 16:15: 'Go and preach the gospel to every creature under heaven:' that is, Go and tell every man without exception, that here is good news for him; Christ is dead for him; and if he will take him, and accept of his righteousness, he shall have him."

The announcement of this good news will be needed from now until the end of the world. Every sinner needs the grace of God. Lawless and unrighteous sinners need it. Self-righteous Pharisees need it. Even people who are trusting in Christ still need the gospel, and need to hear it again. The Marrow of Modern Divinity reminds us of the grace of that gospel. Both the book itself and the explanatory notes by Thomas Boston reassure us that God loves us and has a fullness of grace for us in Jesus Christ.

Phil Ryken is the Senior Minister of Tenth Presbyterian Church in Philadelphia, PA.

Phil Ryken, "Review: The Marrow of Modern Divinity", Reformation 21 (September 2009)

This article was published in Reformation 21, the online magazine of the Alliance of Confessing Evangelicals.  The Alliance calls the twenty-first century church to a modern reformation by broadcasting, events, and publishing.  This article and additional biblical resources can be found at

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