Few ancient Christian authors attempted anything like a complete commentary on the "Gospel of John", among them Origen, John Chrysostom and Augustine. Of these, Augustine's must count as the greatest. Unlike Origen's, it has come down to us in its entirety, and of the others that remain it is certainly the most theologically profound. John's gospel allows Augustine to range broadly over themes that were his life's work - the Trinity, the person of Christ, the nature of the Church and its sacraments, the fulfillment of the divine plan. The 124 homilies that constitute Augustine's commentary, however, are masterpieces not only of theological profundity but also of pastoral engagement. In the question-and-answer style that he frequently employs, for example, one can sense Augustine's real awareness of his congregation's struggles with the gospel text. And the congregation's response to Augustine, which he frequently alludes to, is an indication of the success of his dialogical preaching style. The Johannine literature drew out the best in Augustine." The Homilies on the "Gospel of John" are the indispensible complement to "The Homilies on "The First Epistle of John", recently published in this series, and they should be a part of any serious theological library.

Augustine knows by faith that God is a trinity, Father, Son and Holy Spirit, and he is seeking as far as possible to understand what he believes. In the first seven books Augustine begins by searching the scriptures of the Old and New Testaments for clues to understanding, and then argues in the language of philosophy and logic to defend the orthodox statement of the doctrine against the Arians. In the last eight books Augustine seeks to understand the mystery of the divine Trinity by observing an analogous trinity in the image of God, which is the human mind; and in so doing he also suggests a programme for the serious Christian of spiritual self-discovery and renewal. The Second Edition now features convenient footnotes rather than the previously used endnotes.