The Holy Spirit, once forgotten, has been rediscovered in the twentieth century - or has he? Sinclair Ferguson believes we should rephrase this common assertion: While his work has been recognised, the Spirit himself remains to many Christians an anonymous, faceless aspect of the divine being. In order to redress this balance, Ferguson seeks to recover the who of the Spirit fully as much as the what and how. Ferguson's study is rooted and driven by the scriptural story of the Spirit in creation and redemption. Throughout he shows himself fully at home in the church's historical theology of the Spirit and conversant with the wide variety of contemporary Christians who have explored the doctrine of the Holy Spirit. Foundational issues are surveyed and clarified. Hard questions are explored and answered. Clarity and insight radiate from every page. Here is the mature reflection of a Reformed theologian who will summon respect and charity from those who disagree.