Sanctification in Christ is glorification begun, as glorification is sanctification perfected." The Gospel Mystery of Sanctification was first published in 1692, yet remains today as one of the most authoritative treatments of the subject. Reading Gospel Mystery, one gets a sense that Marshall was peculiarly graced to expound upon sanctification. In treating sanctification, Marshall is adept at amplifying, rather than muting, Reformed distinctives like justification and predestination. Historically this has been a difficult intersection for theologians to navigate yet Marshall manages this exchange masterfully. It is perhaps for this reason Gospel Mystery has had such an enduring legacy, and has served as a powerful salve for the souls of Christians everywhere for over 300 years. Marshall's writing level and style could perhaps be placed at the intermediate for the regular reader of theology. Like many of the divines during the post-Reformation, Marshall poured forth theology thickly, yet profoundly rich and in incredibly well-organized theses. The editors would like to suggest reading this book over long stretches of time (3-4 hours), and preferably with a pencil in-hand for the many notes you will take! To better induct the reader into the world of post-Reformation divines like Marshall, the editors have opted to preserve the original manuscript, and have not changed the text. In addition, extra care w