Puritan pastors of the seventeenth century were true physicians of the soul, and this is made readily apparent in Adam Embry’s study of John Flavel. In Keeper of the Great Seal of Heaven, Embry shows the prominent themes of heavenly mindedness and the work of the Holy Spirit in Flavel’s life and pastoral ministry. He goes on to evaluate Flavel’s teachings about the Spirit, explains Flavel’s view on the sealing of the Spirit, and compares Flavel with other Puritans. Embry further traces the significance of Flavel’s theology of the Spirit in the American Great Awakenings, gives an evaluation of Flavel’s exegesis relating to the sealing of the Spirit, and concludes with an insightful pastoral reflection on the material. While this study reveals a diversity of thought within Puritanism, it also underscores the profound commitment this spiritual brotherhood shared for treating the matter of the heart with biblical truth in dependence on the Holy Spirit.“Loving and reverent reflection on the person and work of the Holy Spirit was at the heart of Puritanism. Whatever else the Puritans were—ecclesial reformers, Reformed theologians—they were above all shepherds of the soul, seeking to understand the ways of the Spirit in the human heart and the local congregation. It was out of this spiritual matrix that some of the Puritans enunciated a theology that centered on what they called the sealing of the Spirit. It is a very important strand of Puritan piety, but relatively little has been written on it. I am thrilled to recommend this study devoted to exploring this theological distinctive in the life and thought of a major Puritan author, John Flavel. Any who are interested in the history of Puritan spirituality are very much in Adam Embry’s debt for this fine study.” — Michael A. G. Haykin, The Southern Baptist Theological Seminary