Augustine on Justification (What Catholics Believe): Part 1
Author: Chris Castaldo, PhD
July 03, 2025
The most significant patristic source of the Protestant Reformation was Augustine of Hippo. In centuries preceding the sixteenth, interest in Augustine had flowered, spawning a widespread attraction to his theology and the order(s) that bore his name. It’s no accident that Martin Luther was an Augustinian, as was Peter Martyr Vermigli. Moreover, we find a steady stream of citations from the old Bishop in John Calvin’s writing, particularly his Institutes.
It is interesting to see Catholics and Protestants sometimes argue about which tradition has a greater claim to Augustine’s legacy. This is especially true regarding the doctrine of justification, where he is a bright-shining luminary (or “fountainhead,” as McGrath puts it) on both sides of the ecclesial divide. In what follows, we won’t tackle that debate but rather try to summarize Augustine’s teaching on justification to clarify the central impulse of his thought. Such knowledge promises to enrich our discussions about salvation with Catholic friends and loved ones.
Augustine’s Doctrine of Justification in a (Small) Nutshell
Perhaps the most crucial concept to clarify concerning Augustine’s doctrine is that justification is a matter of being made righteous. With limited facility in and recourse to the Hebrew and Greek languages, he took the Latin iustificari as meaning “to make righteous.” This approach distinguishes Augustine from the Protestant Reformers, who understood justification to describe God’s activity of attributing or imputing righteousness to the sinner as the ground of acceptance.
As you would expect from the “Doctor of Grace,” such righteousness was recognized to come from God as a gift. So Augustine writes, “God confers righteousness upon the believer by the Spirit of Grace.” And, “This is the Spirit of God by whose gift we are justified.”1
Over and against the teaching of Pelagius, who argued that God offers grace to those who are worthy of it, Augustine insisted that justification is never secured by the autonomous merit of man. The notion that God imparts grace according to human works, he argued, denigrates justification as something owed—a debt—and therefore falls short of grace.
Instead, human merit is regarded as a grace from God: “When God crowns our merits,” Augustine famously declared, “he crowns his own gifts.2 Protestants celebrate Augustine’s championing of grace against Pelagius, but we dissent from the idea that eternal life can be merited by human works (outside the finished work of Christ).
According to Augustine, the justification process begins with baptism, the event in which sin is forgiven. From there, righteousness proceeds to grow in the life of a believer. Because it unfolds gradually (in the process of being made righteous) justification spans the length of one’s life. Here is how Augustine conveys the outworking of such righteousness:
It follows, as I see it, that in whatever kind of degree we may define righteousness in this life, there is in this life no man entirely without sin: there is need for every man to give that it may be given to him, to forgive that it may be forgiven him, and in respect of any righteousness he possesses not to presume that it has come of his own making, but to accept it as the grace of God who justifies; yet none the less to hunger and thirst for the gift of righteousness from him who is the living bread and with whom is the well of life—who so works justification in his saints that labor in the trial of this life….3
In Augustine’s doctrine, the Spirit’s enabling grace empowers one in the growth of justification. Such righteousness is not accessed by faith alone; instead, it is by faith and love. Bear in mind that for Augustine, “faith” describes the act of believing the gospel on the basis of the authority of the apostolic message. To be complete, such faith must be accompanied by love (particularly of God and one’s neighbor). Again, as Augustine put it: “The man in whom is the faith that works through love (Gal 5) begins to delight in the law of God after the inward man; and that delight is a gift not of the letter but of the Spirit.”4
A Central Impulse and Significance of Augustine’s Doctrine
A central emphasis of Augustine’s doctrine of justification is the believer’s ethically engaged participation in the life of Christ, a participation empowered by the Spirit that grows and manifests itself in greater levels of love. In Alister McGrath’s words, “For Augustine, it is love, rather than faith, which is the power that brings about the conversion of people.”5 If I were to express this Augustinian impulse in terms that I hear from Catholic friends, it would be something like this: God, by his Spirit and according to his grace, fortifies the souls of believers with righteousness so they will increasingly embody the love of Christ and merit eternal life.
How then should Protestants think about Augustine’s doctrine, especially in conversation with Catholic friends? In Part 2 next week, I’d like to offer some thoughts.
Notes:
1 John Burnaby, Augustine: Later Works, Library of Christian Classics, vol 8, (Philadelphia, Westminster, 1980), 15: 205.
2 Eugene TeSelle, Augustine the Theologian. (Oregon: Wipf and Stock, 2002), 329.
3 Burnaby, Augustine, 65: 249, 250.
4 Ibid., 26:215.
5 Alister E. McGrath. Iustitia Dei: A History of the Christian Doctrine of Justification. 3rd ed. (Cambridge: Cambridge University Press, 2005), 46.
Chris Castaldo is Lead Pastor of New Covenant Church in Naperville, Illinois.
Image: Saint Augustin by Philippe de Champaigne, c. 1645. Public Domain.
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