Firstly the article approaches the experience of St. Augustine as a listener of sermons and places the subject of homiletics in the field of practical theology.Secondly, it collects some fundamental ideas about rhetoric at the service of Christian preaching according to St. Augustine.Thirdly, it points to the current crisis of preaching to conclude with the formulation of three challenges that the homiletic thought of St. Augustine release to today homily.These three challenges are articulated precisely with the three purposes of Christian preaching according to St. Augustine: teaching, delighting and inspiring.Well-articulated, these three objectives could avoid the current risks of irrationalism, emotionalism and practicality in homily.