Abba Ammonas was a disciple of St. Anthony the Great and his successor in directing the brethren dwelling in the Outer Mountain after the repose of St. Anthony. From his sayings, not only do we learn that he lived for a time in Scetis and was ordained as a bishop, but also that he was one of the greatest and most peculiar desert personalities of the fourth century. His letters, thirteen in number, reveal the inner thought of Abba Ammonas, of someone who had a firsthand, profound monastic experience, who had seen, tasted, and lived the true and unspotted monastic life. He elucidates with such clarity of thought and ingenuity of expression the mysteries of the pure monastic life-and the spiritual life in general-fitting of a disciple of the father of monasticism, as someone who is intimately acquainted with the Christian struggles, the demonic warfare and how to overcome them, the consolations and joys of the Christian way of life, the work of grace, the virtues and their acquisition. Thus, this book is requisite for every Christian striving to live a genuine Christian life.