Raniero Cantalamessa, OFM Cap, is past professor of the history of Christian origins at the Catholic University of Milan and a member of the International Theological Commission. He is preacher to the papal household and author of The Mystery of Pentecost, Easter in the Early Church; The Eucharist: Our Sanctification; The Mystery of God's Word; The Holy Spirit in the Life of Jesus; Jesus Christ, The Holy One of God; Mary, Mirror of the Church; The Mystery of Christmas; and The Mystery of Easter published by Liturgical Press.