An accessible study aid for adult catechesis and religious education prepared by a special theological commission established by The Central Organizing Committee for the Great Jubilee of the Year 2000 at the Vatican, this book follows Jesus Christ, Word of the Father: The Savior of the World. It is the second in a series of four volumes, on the Son, the Spirit, the Father, and the millennial year itself, to be published one per year to assist adults in their preparation for Holy Year 2000. This book offers a general overview of the mystery of the Holy Spirit, taking up the theme designated for the year 1998 in Pope John Paul II's encyclical On the Coming of the Third Millennium: "a renewed appreciation of the presence and activity of the Spirit."