A scripturally based, comprehensive theology of the Holy Spirit, this book discusses the Spirit in the context of our own Christian tradition as well as in connection with the world's religions, the world at large, and―drawing on the author's own Teilhardian orientation―creation and the cosmos. It is unique in going beyond the traditional theological treatments of the Holy Spirit to formulate this all-encompassing approach. It discusses the presence of the Spirit in our personal spiritual lives, the indwelling Spirit in the depth of our souls. Then it moves to the Holy Spirit's role in the church, giving birth to the Church, animating the church with her charisms, at the source of Word and sacrament, after having seen how the Holy Spirit is integrally involved in the life of Jesus as well. It then connects the Holy Spirit to the religions of the world, at the source of the major religious traditions, the source of their unity and diversity. The book then emphasizes the Spirit's presence and action in the world beyond the religions, in movements for justice and peace. The whole world is the Spirit's sphere of influence, including the wider creation and cosmos. It includes the role of the Spirit in creation and at the heart of an evolving universe, the Creator Spirit or cosmic Spirit. In the end the book comes back to our own life in the Spirit and the challenge of living in the Spirit or acquiring the Spirit as the goal of the Christian life.