The Marrow of Modern Divinity by Edward Fisher (1627-1655)
"The gospel method of sanctification, as well as of justification, lies so far out of the understanding of natural reason, that if all the rationalists in the world, philosophers and divines, had consulted together to lay down a plan, for repairing the lost image of God in man, they had never hit upon that which the divine wisdom had pitched upon, viz., That sinners should be sanctified in Christ Jesus, 1 Cor. 1:2, by faith in him, Acts 26:18. Nay, being laid before them, they would have rejected it with disdain as foolishness, 1 Cor. 1:23."
Click to hear The Marrow book (a dialog) read by various readers, free at Archive.org.
EXCERPT (5 mins.): The Dangers of Legalism (Sinclair Ferguson, 2004)
Republished many times since 1645, The Marrow of Modern Divinity has ever been controversial, as a litmus test for legalism. Thomas Boston (1676-1732) republished The Marrow in 1726 with his own extensive notes, including this caution: "Reader, lay aside prejudices—look and see with thine own eyes...and thou shalt find no Antinomianism taught here; but thou wilt be perhaps surprised to find, that the tale is told of Luther and other famous Protestant divines."
"Anyone who comes to grips with the issues raised in The Marrow of Divinity will almost certainly grow by leaps and bounds in understanding three things: the grace of God, the Christian life, and the very nature of the gospel itself. I personally owe it a huge debt."—Sinclair Ferguson.
The Whole Christ: Legalism, Antinomianism, and Gospel Assurance; Why the Marrow Controversy Still Matters (Sinclair Ferguson, 2016)
Appendix: Excerpt from Thomas Boston's Marrow Notes on Faith
Pastoral Lessons from the Marrow Controversy
EXCERPT: "So we must beware of seeking a balance between legalism and antinomianism. After explaining the justification of the ungodly, Paul anticipates the logical question: 'Are we to continue in sin the grace may abound?' (Ro 6:1). The legalist replies to Paul's question, 'Not on your life! Don't you know that if you still fall into sins--especially the same ones repeatedly--you either lose your salvation or never had it to begin with?' If our view of justification does not provoke this charge of antinomiansim, it has missed Paul's point... Instead, Paul's answer stands in sharp contrast to both legalism and antinomianism. He does not advocate for a balance between these extremes. Rather he turns to the gospel as an alternative to both [pg. 308].