"I have...the sure hope that this work will encourage, even today,a direct contact with the writings and the thoughts of Therere, letting the reader be won over by her existential witness," so writes the author in his introduction. Archbishop Celli originally published five articles on the missionary vocation of St Therese of Lisieux, from 2000 to 2004, for the magazine Omnis Terra of Pontifical Missionary Union, which is published in various laguages. These articles were a summary of his doctoral thesis in theology on the same subject that was published in the series, "Spiritualitas," of the Lateran Pontifical University, in 1969. On this occasion he had not made substantial changes because he is convinced that his analysis conducted in the years 1966-1969 on the writings of Therese remain valid despite the passage of time. In republishing the articles in this book, he has made changes and expanded certain parts of the articles. He is aware that many good studies of the theological and spiritual doctrine of St Therese of Lisieux have been published, and many of them have been the subject of an appropriate and careful reading on his part.