As editor of a remarkable new series entitled ``Rekindling the Inner Fire,'' David Hazard is reintroducing classic Christian authors to today's readers. In Spirit, he offers us St. John of the Cross, one of the foremost mystics of the Christian faith. Designed perfectly for Lenten reading, the book is organized into 40 readings culled from the great works of this 16th-century Spanish mystic (some of the finest in Christian literature-Dark Night of the Soul, etc.) and paraphrased by Hazard to make the materials more accessible and applicable to a contemporary reader. Each selection is preceded by appropriate scripture passages and followed by a thoughtful prayer reflecting upon the reading. A word of warning: the spirituality espoused by John of the Cross is not the sweet, comfortable spirituality currently in vogue. For example, John would no doubt find the contemporary concern with self-esteem a matter of grasping pride. John's call instead is to self-denial and true knowledge of God-after the sin and untruth have been burned away from our souls. But, despite the seeming harshness of John's teachings, most readers will find this book a mere appetizer and will want to follow it by trying the works of St. John in their entirety.