by Kenneth D. Boa & Robert M. Bowman, Jr.

In the fourth and fifth centuries, pagan religions were on the wane and Christianity was on the ascendancy throughout the empire, particularly after the edict of Constantine in 313.  Christian apologists, both Latin and Greek, wrote with pride of the progress and life-changing effects of Christianity.  They also became more systematic in their presentation of Christianity as a worldview in contrast to competing philosophies, notably Neoplatonism.

The greatest apologist and theologian of this period and indeed of the first millennium of Christian history was, by nearly everyone’s reckoning, Aurelius Augustine (354-430), the bishop of Hippo, whose apologetic and theological writings ranged widely over the areas of human culture, philosophy, and history.1  Augustine was won to the Christian faith after trying Manicheism, a dualistic philosophy that viewed both good and evil as ultimate realities, and Platonism, which convinced him that Manicheism was false and so, by his own testimony, helped him on the path to Christianity.  His earlier apologetic works, not surprisingly, were in large part devoted to refuting Manichean philosophy (On the Catholic and Manichean Ways of Life, Of True Religion, On the Usefulness of Belief).


A Christian View of the World and History

As Augustine became more involved in church life, his apologetic works became more diversified.  Over the course of his life he wrote numerous works championing Christianity over paganism, refuting heresies plaguing the church, and expounding Christian truth in a positive manner in teaching manuals and in sermons for the edification of Christians.  An original and multi-gifted writer, thinker, and scholar, Augustine was able to develop an apologetic that was built on a stronger metaphysical or worldview base.  While his worldview was at first heavily Platonic, as he matured his theology and philosophy became significantly less Platonic and more and more biblical.  Specifically, Augustine became the first Christian theologian and apologist to embrace a thoroughly Pauline view of faith and of God’s sovereignty in salvation and in human history.  This Pauline theology, in turn, enabled him to develop the first philosophically sophisticated, biblically sound, and comprehensive Christian view of the world and of history.  Such a Christian philosophy was necessary to combat pagan philosophies, including Platonism, the philosophy he considered closest to Christianity.  All such philosophies were corrupt and incapable of bringing people to God.  Augustine’s Christian philosophy was expounded most fully in one of his last works, The City of God, widely regarded as one of the five or ten most important books in the history of Western thought.1


Faith Seeking Understanding

Augustine’s teaching on apologetical issues has inspired apologists and theologians from his day to the present.  In his approach, faith and reason are interactive in coming to know the true God in Jesus Christ.  Reason precedes faith in that a rational mind and recognition of the truth of what is to be believed must exist if we are to believe anything.2  But faith precedes reason in that the truths of the Christian faith are in large part unseen—not only is God invisible, but the redemptive acts of God in Jesus Christ occurred in the past and cannot be directly witnessed.  Because these truths cannot be seen, they must be accepted on the authority of God’s revelation as given in Scripture and witnessed by the church.3  These truths can then be understood as the believer comes to appreciate their significance from the inside.  “For understanding is the reward of faith. Therefore do not seek to understand in order to believe, but believe that thou mayest understand.”4  Augustine, then, was the first apologist to enunciate the principle of believing in order to understand, or faith seeking understanding (fides quaerens intellectum), but for him it was only one side of the coin.  He frequently expressed this interactive or interdependent view of faith and reason in such statements as “For faith is understanding’s step; and understanding faith’s attainment.”5  Moreover, he emphasized (in his later writings) that both faith and reason are enabled by God’s grace.  He declared that “no one is sufficient for himself, either to begin or to perfect faith; but our sufficiency is of God.”6


A Reasonable Faith

This does not mean that non-Christians know nothing about God.  Augustine cited Romans 1:20 to show that some philosophers, especially Platonists, have been able from the creation to recognize the fact of a Creator God.  The line of reasoning by which even pagans can be made to admit a Creator is essentially what philosophers would later call a cosmological argument, reasoning from the changeableness of all things in the world (Greek cosmos) to the existence of an unmade Maker of all things.  This was one of a number of arguments by which Augustine reasoned that knowledge of God was available to pagans.7  But this knowledge cannot prevent them from falling into idolatry and polytheism.8  The true worship of God can be found only by placing faith in Jesus Christ.


Such faith is not a groundless faith: “they are much deceived, who think that we believe in Christ without any proofs concerning Christ.”9  Augustine wove the proofs he found compelling into an apologetic consisting of a number of strands. These proofs included fulfilled prophecy, the consistent monotheistic faith and worship of the church, the miracles of the Bible, and especially the “miracle” of the massive conversion of much of Roman society to faith in a crucified God even when such faith brought martyrdom.10


Kenneth D. Boa is the President of Reflection Ministries.  Robert M. Bowman, Jr. is the manager of Apologetics and Interfaith Evangelism for the North American Mission Board of the Southern Baptist Convention.  This article is adapted from their book, Faith Has Its Reasons: An Integrative Approach to Defending Christianity (NavPress, 2001).



1Augustine’s many works are most accessible in English in A Select Library of Nicene and Post-Nicene Fathers of the Christian Church, 1st ser. (Grand Rapids: Eerdmans), hereafter cited as NPNF. Three of his most important works are conveniently available in one volume found in almost every public library: Augustine, The Confessions; The City of God; On Christian Doctrine, Great Books of the Western World, vol. 18 (Chicago: Encyclopaedia Britannica, 1952). The literature on Augustine is enormous. Books of special relevance to Augustine’s apologetics include B. B. Warfield, Studies in Tertullian and Augustine (New York: Oxford University Press, 1930); Roy W. Battenhouse, ed., A Companion to the Study of St. Augustine (New York: Oxford University Press, 1955); Gordon R. Lewis, “Faith and Reason in the Thought of St. Augustine” (Ph.D. diss., Syracuse University, 1959); Étienne Gilson, The Christian Philosophy of St. Augustine, trans. L. E. M. Lynch (New York: Random House, 1960); Eugene Portalie, A Guide to the Thought of Saint Augustine, trans. Ralph J. Bastian, Library of Living Catholic Thought (Chicago: Henry Regnery, 1960); Ronald H. Nash, The Light of the Mind: St. Augustine’s Theory of Knowledge (Lexington: University Press of Kentucky, 1969); Terry L. Miethe, comp., Augustinian Bibliography, 1970-1980: With Essays on the Fundamentals of Augustinian Scholarship (Westport, Conn.: Greenwood, 1982); Norman L. Geisler, ed., What Augustine Says (Grand Rapids: Baker, 1982); Henry Chadwick, Augustine (New York: Oxford University Press, 1986); Curtis Chang, Engaging Unbelief: A Captivating Strategy from Augustine & Aquinas (Downers Grove, Ill.: InterVarsity Press, 2000), especially 40-52, 66-93. The periodical Augustinian Studies has published numerous relevant articles, for example, J. Roland E. Ramirez, “The Priority of Reason over Faith in Augustine,” Augustinian Studies 13 (1982): 123-131. Other studies worth noting include Demarest, General Revelation, 25-31; Mayers, Balanced Apologetics, 85-96; Sproul, Gerstner, and Linsley, Classical Apologetics, 189-96; Craig, Historical Argument, 53-60; Norman Kretzmann, “Faith Seeks, Understanding Finds: Augustine’s Charter for Christian Philosophy,” in Christian Philosophy, ed. Thomas P. Flint (Notre Dame, Ind.: University of Notre Dame Press, 1988), 1-36; Dewey J. Hoitenga, Jr., Faith and Reason from Plato to Plantinga: An Introduction to Reformed Epistemology (Albany: State University of New York Press, 1991), 57-142; Abraham P. Bos, “Augustine (354-430),” in Bringing into Captivity Every Thought, ed. Klapwijk, et. al., 49-66; Byron Bitar, “Augustine, Natural Theology, and General Revelation” (paper presented to the Evangelical Theological Seminary annual convention, 1997); Kenneth Richard Samples, “Augustine of Hippo,” in 2 parts, Facts for Faith 1 (2001): 36-41; 2 (2001): 34-39; Dulles, History of Apologetics, 73-85.

2On The City of God, see John Anjola Laoye, “Augustine’s Apologetic Use of the Old Testament as Reflected Especially in the ‘De Civitate Dei’” (Th.D. diss., Southern Baptist Theological Seminary, 1972); Ford Lewis Battles, Augustine: City of God, Study Outline 9 (Pittsburgh: Ford Lewis Battles, 1973).

3Augustine, Epistles 120; On the Predestination of the Saints 2.5; On the Spirit and the Letter 31.54.

4City of God 11.3-4; Confessions 7.9.14; Epistles 120; etc.

5Tractatus on the Gospel of John 29.6 (NPNF, 7:184).

6Sermons 76.1-2 (NPNF, 6:481).

7On the Predestination of the Saints 2.5.

8City of God 8.5-6, 10; cf. Tractatus on the Gospel of John 2.4. On Augustine’s arguments for the existence of God, besides works already cited, see John A. Mourant, “The Augustinian Argument for the Existence of God,” in Inquiries into Medieval Philosophy: A Collection in Honor of Francis P. Clarke, ed. James F. Ross, Contributions in Philosophy, vol. 4 (Westport, Conn.: Greenwood Publishing, 1971); J. Roland E. Ramirez, “Augustine’s Proof for God’s Existence from the Experience of Beauty: Confessions, X,6,” Augustinian Studies 19 (1988): 121-30.

9Augustine, City of God 8.12.

10On Faith in Things That Are Not Seen 5 (NPNF, 3:339).

11Ibid., 5-10; City of God 22.1-5.