Matthew Levering, in his celebrated new introduction to The Theology of Augustine using his seven key works, writes:
Augustine wrote over one hundred treatises, countless letters and sermons, and more than five million words in all. Although few scholars can become acquainted with all of his writings, there are certain pivotal works that one simply must know if one is interested in the development of Christian theology, biblical exegesis, and Western civilization. . . .
In order to engage later Catholic and Protestant theology—and in certain cases Eastern Orthodox theology—one must know these works.
Even more important, one must read these works to gain an appreciation for why such a great thinker gave his life to the realities proclaimed by Christian Scripture.
And, lastly, it is by reading these works that one will be able to evaluate the development and present intellectual impasse of Western civilization.
Augustine speaks as powerfully today as he did sixteen hundred years ago.
Levering then explains the seven works he has chosen. I’ve added links below to the translations from The Works of Saint Augustine: A Translation for the 21st Century (New City Press), an ongoing project to render the complete works of Augustine in English.
My task in this book is to present these seven pivotal works of Augustine. Here we find the themes that Augustine plumbed most deeply: how to interpret Christian Scripture, the relationship between the Old and New Testaments, the unity of the Church in charity, God’s eternity and simplicity, grace and predestination, conversion, the meaning of history, the two “cities,” the cross and resurrection of Jesus Christ, and the divine Trinity.
The first two works, On Christian Doctrine and Answer to Faustus, a Manichean, set forth the central components of Augustine’s theology of Scripture and of scriptural interpretation.
The next two works, Homilies on the First Epistle of John and On the Predestination of the Saints, explore the grace of the Holy Spirit and the charity that unites the Body of Christ.
The final three works, Confessions, City of God, and On the Trinity, form a triptych that shows how human life (individual and communal) is an ascent to full participation in the life of the Triune God, who descends in Christ and the Holy Spirit to make possible our sharing in the divine life.
You can read Dr. Levering introduction and his first chapter (about On Christian Doctrine) here.