The content of this volume constitutes the Warfield Lectures, delivered in February, 1964, and later to be delivered at the General Council of the World Alliance of Reformed Churches, in Frankfurt-on-Main. Recognizing that many new insights in the field of Biblical theology have not yet been incorporated into a theology concerned with the Holy Spirit, the author aims at contributing to a revival of interest in the doctrine of the Spirit, as well as a practical engagement with the meaning of The Holy Spirit in the faith and life of the Church and of the individual. After an opening chapter on the relationship of The Spirit to Christ, the author develops his theme with the rather unexpected and unusual subject of the bearing of The Spirit upon the Mission of the Church. This is followed by lectures on the relation of The Spirit to the Church as institution, to the regeneration of the individual, and then to Creation and history. The final lecture deals with the subject at the point where conventional discussions often begin: the Spirit as the Third Person of the Trinity. Extensive use is made of Biblical exegesis and of traditional and contemporary theological resources, the dominant theological approach being strongly grounded in Reformation theology. Although a scholarly work, even amateur theologians will find the book readable and enlightening.