This volume contains 200 letters from, for the most part, canonized or beatified saints of the Roman Catholic Church, but also from men and women whose lives are less officially recognized as exemplary. The introduction describes the principles governing choice, and the main varieties of saintliness, which does not exclude humour, severity, testiness and anecdotal ability. The "sinners" of the title are such in the sense that anyone other than a saint may be taken to be a sinner. They may be close members of the saint's family, religious superiors or inferiors, monarchs, politicians and even popes. Some of the letters are fiercely corrective, sometimes they are full of the joys - or trials - of holiness. They analyze the age, great historical events or private matters of the heart. All the letters are revealing or instructional works in their own right, offering matter for meditation, healing reflection and enjoyment. They are grouped thematically, with short, prefatory and biographical notes referring to their historical context. The book can be read from beginning to end, or selectively according to topic, or by reference to individual letter-writers. The book thus provides a source for exploring the nature of saintliness across the centuries. It is also a manual of comfort, advice and entertainment. The courage, compassion, hope, determination, faith, love and apostolic spirit of the writers speak to modern readers in ordinary circumstances and at the moral crossroads of their lives. The saints chosen include such pre-eminent letter writers as Bernard of Clairvaux, Teresa of Avila and Thomas More, and a host of others as diverse as Maximilan Kolbe, Gerard Manley Hopkins, Charles de Foucauld, John Donne, Charles Wesley, Simone Weil and Dietrich Bonhoeffer. John Cumming is the co-author (with Bishop David Konstart) of "Beginnings", and executive editor of the "Dictionary of Psychology" and "Encyclopedia of Theology".