Augustine on Justification (What Protestants Believe): Part 2
Author: Chris Castaldo, PhD
July 10, 2025
Editor’s note: Last week in Part 1, Pastor Chris showed how Protestants and Catholics look to Augustine of Hippo for guidance concerning the doctrine of justification. We also explored the Catholic understanding, which focuses on human merit. In Part 2, we learn what true justification is—and what it isn’t.
Given the Catholic understanding of justification—that it is a process in which one becomes increasingly righteous—the assertion that God accepts us by “faith alone” often sounds like “cheap grace”(to borrow a phrase from Dietrich Bonhoeffer). It sounds like we’re saying, “Don’t worry about pursuing a life of holiness. Just say this sinner’s prayer, walk this aisle, and then you’ll be safe for all of eternity.” Thus, for Catholics, standing on the shoulders of Augustine, our doctrine of justification may appear to be a form of fire insurance that requires a minimal investment in exchange for an eternal payoff.
So our opportunity among Catholic friends is to explain what we mean by “faith alone,” that humanity is incapable of meriting the smallest amount of divine favor by performing acts of love, and that God therefore gives the gift of Christ’s righteousness as the basis of our acceptance, a gift that comes only through faith. But this should not denigrate the importance of tangible love in the larger outworking of salvation. As the Reformers put it, justification is by faith alone, but not by a faith that remains alone.6
Or as John Calvin stated, “For we dream neither of a faith devoid of good works nor of a justification that stands without them.”7 The same emphasis continued among subsequent evangelicals, as Jonathan Edwards wrote, “And one great thing he [Jesus] aimed at in redemption, was to deliver them from their idols, and bring them to God.”8
Relating Faith to Acts of Love
An old professor of mine liked to explain the need for tangible acts of love in salvation in terms of a Costco card. Most parts of the country probably have a Costco or equivalent. It is a membership warehouse chain where customers enjoy discounts on various products because merchandise is purchased in bulk. The decisive transaction that provides access to Costco occurs when one becomes a member. You simply pay the fee, get your membership card with embarrassing photo, and shop to your heart’s desire.
Whenever you visit the store, you must present your card to the nice lady at the door to verify that you have paid the requisite price of membership. This card-showing exercise, which is performed in all subsequent visits, simply confirms that you have already completed the membership transaction.9
So it is with works of love in salvation. Our virtuous behavior can never procure or somehow enhance God’s favor toward us. The cost of forgiveness and new life is infinite, and we are utterly bankrupt. Only Christ can complete the transaction for us (the membership fee), which he did by shedding his blood. By dying on the cross as our substitute and rising from the dead, Jesus enabled us to approach the throne of grace confidently. But not only do we have confidence, God has also sent his Holy Spirit to live within us and has blessed us with every spiritual blessing in heaven in order for the Church to walk in good works, which he prepared beforehand.
Therefore, while we maintain that justification is by faith alone, we must regard salvation as much more than a sinner’s prayer that gets us into heaven. God’s unmerited favor must take the form of an obedient life of faith here and now, as Paul the Apostle writes: “Since we have these promises, dear friends, let us purify ourselves from everything that contaminates body and spirit, perfecting holiness out of reverence for God” (2 Cor. 7:1, niv). This Pauline notion is also deeply Augustinian.
Notes:
6 Or in the Westminster Confession: “Faith, thus receiving and resting on Christ and His righteousness, is the alone instrument of justification: yet is it not alone in the person justified, but is ever accompanied with all other saving graces, and is no dead faith, but works by love.” Westminster Confession of Faith. “Of Justification,” Chap. 11.2.
7 John Calvin. Institutes of the Christian Religion, 2 vols., ed. John T. McNeill. trans. Ford Lewis Battles (Louisville: Westminster John Knox Press, 1960.) 1:798 (3.16.1).
8 Jonathan Edwards, The Works of Jonathan Edwards, Vol 2, “Discourse: Men Naturally are God’s Enemies” (1834 reprint, Peabody: Hendrickson Publishers, 1998), 139
9 Like all analogies, there are a few points where the Costco card breaks down, like when your membership is complete you must purchase another one. You will also perform another monetary transaction when you buy products from the store. For some reason, I find these payments are always quite large.
Chris Castaldo is Lead Pastor of New Covenant Church in Naperville, Illinois.
Image: Saint Augustin by Philippe de Champaigne, c. 1645
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