This work was published posthumously in 1659 from sermon notes the author left behind, and many times after that. If, as Charles Hodge said, the greatest conviction a man could have is the conviction of sin, then the greatest assurance a man can have is the assurance of salvation. Sin our day, when assurance is offered promiscuoulsy to persons who give little evidence that a work of grace has taken place in the heart, this work is sorely needed. One popular writer has said that a person can be a practicing atheist, commit murder every day, and, if he once made a "decision" for Christ, is certain of dwelling eternally in the presence of God. The theological term for this, coined by Martin Luther, is "antinomianism." Today we call it "easy believism." The Bible calls it "another gospel which is no gospel." Let Shepard, like a surgeon, use the Scripture to lay open your heart. You will know, after reading this book, if you are a wise or foolish virgin!