Augustine’s sermons provide a unique source in explaining his influence from the 5th century onwards as a theologian and pastor, a minister of the Word preached and celebrated in the sacrament. Of particular value in this regard are his sermons on the Psalms. Issues of authenticity are also considered in this article. The influence of Augustine’s sermons was widespread through their tradition and adaptation by others. A substantial and reliable corpus of his sermons is available today. As a pastor, Augustine was anxious to challenge heresy in his preaching, especially to confront the Donatists, Manichaeans and Pelagians. His preaching is considered in the wider context of congregational worship with its origins in the synagogue. Of special importance are his preaching techniques, while his doctrine of ‘the inner teacher’ (magister interior) is equally significant. Essential elements of Augustine’s theory and practice became influential in the early days of the Protestant Reformation (Luther, Calvin and others). The author briefly touches on the question of their relevance for today’s congregational worship.