While justification is an act of God and is something he graciously does on behalf of sinners, this does not mean human beings are passive in every respect. Human beings must believe in Jesus. Upon believing, God’s response is to justify the ungodly (Rom 4:5).
This exercise of faith is not a work that seeks to earn, but receives the salvation that is freely offered in Jesus. In John 1, believing is parallel to receiving. “He came to his own, and his own people did not receive him. But to all who did receive him, who believed in his name, he gave the right to become children of God, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God” (John 1:11–3). To receive Jesus is to believe in Jesus. Calvin writes, “For with respect to justification, faith is a thing merely passive, bringing nothing of our own to conciliate the favor of God, but receiving what we need from Christ.” Though Calvin says faith is “passive,” he does not mean that there is no act of the will. Instead, he means that faith is “passive” in the sense that it does not actively pacify (“conciliate”) God. Instead, faith receives or apprehends Christ, who is the propitiation for our sins (cf. 1 John 2:2; 4:10).
Borrowing from Aristotelian categories, the Reformed tradition explains faith as the instrumental cause that leads to God’s gracious act of justification (Rom 5:1). Again, Calvin strikes the correct note when he writes, “faith of itself does not possess the power of justifying, but only in so far as it receives Christ.” In other words, faith is the instrument by which the sinner takes hold of Christ. The Belgic Confession states, “faith is an instrument that keeps us in communion with [Christ] and all His benefits…” The Westminster Confession (WCF) agrees, “Faith, thus receiving and resting on Christ and his righteousness, is the alone instrument of justification.”
Some, however, have objected to the idea of calling faith the instrumental cause. John Owen notes that the hesitancy of some is due to the “unscriptural notion” of this Aristotelian category. Owen responds by reminding his readers that this hesitation is unwarranted and cites the classical understanding of God as “a trinity of persons” as evidence that Christians have often used words and concepts outside the pages of Scripture to make sense of theological realities. Thus, to say that faith is the instrumental cause of our justification captures the biblical reality and Reformed position that though faith is a human act, it merely takes hold of Christ, who is the sole ground of our justification. That is, justification does not depend on the intrinsic value of faith. Instead, our confidence is sought “only in the terrors of Christ our Redeemer,” who is apprehended by faith alone . The Belgic Confession states the point clearly when it says, “we do not mean, properly speaking, that it is faith itself that justifies us—for faith is only the instrument by which we embrace Christ, our righteousness.”
Viewing faith as the instrumental cause of justification because it embraces Christ and his benefits (i.e. remission of sin and imputed righteousness), however, is challenged by various sects. For instance, Socinianism impacted the discussion of justification sola fide, even when it came to the subject of justifying faith. Socinianism fell well outside of the Reformed tradition and outside of historic Christian orthodoxy. Socinians rejected the Trinity, penal substitution, and the Protestant idea of justification. In regard to justifying faith, Turretin notes that according to Socinianism, “faith or act of believing is the cause of justification so that there is no other immediate and formal righteousness by which we are just before God than our faith.” Thus, the Socinians rejected any concept of imputed righteousness. Faith itself, apart from imputed righteousness or a penal-substitutionary death, was itself the cause of justification. But how is faith the cause for Socinians? Mastricht gets us close to the idea when he writes the following:
The Socinians, that they might more effectively remove the satisfaction and merits of Christ from saving faith as well as from the Christian religion, and maintain that we are justified not by faith alone in Christ, but by observance of the commands of Christ, and thus by “evangelical works,” as they love to say, state that saving faith does not consist of anything but observance of the commands of Christ. [emphasis added]
The point here is that though both the Reformed and Socinian positions argued for faith, the way faith worked in justification for Socinians radically departed from the Reformed position. For Socinians, faith justified because faith was merely the observing of God’s commands (thus, righteous works). For the Reformed, faith “chiefly consists in the reception of God as the supreme end and Christ as the one and only Mediator.” Therefore, we can say, faith justifies not because it is a good work, not because it does, but only because it receives Christ.
Therefore, faith was and is considered a human act that takes hold of Jesus. Of course, the act of faith is itself a gift of grace (Eph 2:8–9). Though there is some debate about what “the gift” (Eph 2:8) refers to specifically in Ephesians 2, it seems best to take salvation as a whole as the antecedent. Yet, the gift certainly includes faith since “by grace you have been saved through faith” (Eph 2:8). Therefore, the faith that we place in Jesus is not something men and women conjure up in their own power. Given what we have noted in a previous post about the priority of grace, the will cannot move in faith towards God on its own apart from God’s internal work of grace. Instead, faith is a gift and Spirit-wrought human act, the “principle work of the Holy Spirit.”
Yet, this act is not a simple act. For the Reformed, the act of faith involved various elements. For instance, the Reformed tradition believed faith included at least notitia, assensus, and fiducia. That is, the exercise of faith included knowledge (notitia) of certain realities, assent (assensus) to their veracity, and a trust (fiducia) in a person, namely Jesus.
In addition to knowledge, assent, and trust, faith was described in the tradition as including various faculties of the soul. This point is important and will find more attention in a future post. Here it is sufficient to provide one example. For instance, Peter van Mastricht described the act of faith in diverse ways. He writes, “We call this faith an act—an act of the rational soul that consists in receiving God as the end and Christ as the Mediator.” This act of the soul was “of the whole soul” and included each of the “soul’s faculties—the intellect, the will, the affections, and so forth.” Clearly, for the Reformed, this act of faith was more than simple acknowledgment of truth, but included various elements. Again, we shall return to this point in a future post as we dissect in more detail the ontological character of justifying faith. For now, we simply conclude that the Reformed tradition believed mankind must exercise faith, an act that included various faculties of the soul, if they would be justified before God.
To say, however, that we are justified by grace through faith is not in and of itself controversial, at least for Christians who read the Bible. Rome and the Reformers could both assert justification by faith. The point of contention between Protestants and Catholics is felt when the word “alone” is added to the discussion. Luther had included the word “alone” or “only” in his 1522 translation of the New Testament. Luther translated Rom 3:28 as, “We hold, therefore, that someone becomes righteous without the work of the law, only through faith.” Though Luther seems to understand justification in transformative terms at this point in his ministry (he is, after all, a Medieval man groomed in Augustinianism), the important point here is the introduction of the world “only.” It is beyond our purposes here to evaluate Luther’s translation. The historical-theological importance is our main concern and was not something missed by Roman Catholics.
At the Council of Trent, the idea that we are justified sola fide is explicitly condemned. According to Rome, faith was a necessary but not a sufficient condition for justification. As De Chirico notes,” According to Trent, faith alone is an anthropological impossibility… a soteriological conundrum…[that] excludes the primary and necessary sacramental mediation of the church.” In other words, sola fide led sinners away from the sacramental system when it came to how one could be counted righteous before a holy God. Rome could not countenance a position that undermined the centrality of the Church in the salvation of sinners. Yet, the Reformed tradition has vigorously defended the assertion that sinful men and women are justified by faith alone, apart from any internal worth or merit, or any necessary participation in the sacraments of the Church.
Simply stated, though the phrase “justification by faith alone” does not exist in the Bible, it does capture the biblical idea. The Reformed tradition has spilled large amounts of ink to drive the theological point home. John Calvin engages with “the Sophists” who “dare not deny that man is justified by faith because it recurs so often in Scripture.” Yet, “since the word “alone” is nowhere expressed, they do not allow this addition to be made.” He takes up the objection of the Sophists who say that justification apart from “works of the law” refers specifically to the ceremonial works of the law…not the moral works.” Calvin disagrees. He quotes several passages (Gal 3:10, 12, 21–22; Rom 3:20, 27; 4:4–5, 15) to show how Paul has “the whole law” in view. The moral and ceremonial laws are excluded and therefore “Not only by a false but by an obviously ridiculous shift they insist upon excluding this adjective [i.e. alone].” For Turretin, faith alone made sense because it pointed towards the reality that our only hope is the righteousness of Christ, and faith “alone apprehends” this righteousness. Taking hold of the righteousness of Jesus did not come through the keeping the law or exerting moral effort, but “by faith alone.”
In summary, Paul’s inference in Rom 5:1 is on point. “Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ.” The Reformed tradition has followed suit, asserting that justification is via faith not because faith is inherently virtuous and thus meritorious, but because faith alone apprehends Christ and his righteousness. Therefore, the Heidelberg Catechism asks: “How are you righteous before God?” Answer: Only by faith in Jesus Christ…” Indeed, the only hope for humanity is to take hold of Christ by the instrumental means of sola fide. In taking hold of Christ by faith, there is remission of sin and the imputation of the alien righteousness of Jesus. And, of course, this faith that justifies will not be alone, as justified men and women give their lives to loving God and loving neighbor.
Yet, at least one question remains. When we say that faith justifies, how do we define faith? That is, what is faith? That’s a question of ontology and a question the Reformed tradition has sought to explain in detail. To that question, I turn. When I’ll be able to provide some clarity, I do not know 🙂
 Calvin, Justification, 3.5.
 Ibid., 1.4. The doctrine of propitiation refers to how Christ has satisfied the wrath of God by dying in the place of sinners. Grudem states that propitiation is “a word that means “a sacrifice that bears God’s wrath to the end and in so doing changes God’s wrath towards us into favor” (Wayne A. Grudem, Systematic Theology: An Introduction to Biblical Doctrine (Leicester, England: Grand Rapids, MI: Inter-Varsity Press ; Zondervan Pub. House, 1994), 575). A detailed linguistic study is found in Leon Morris, The Apostolic Preaching of the Cross, 3. ed., reprint. (Grand Rapids, MI: Eerdmans, 1987).
 The language of instrumental means is common language in understanding the doctrine of justification. Calvin writes, “I say that faith, which is only the instrument for receiving righteousness… (Calvin, Institutes, 734). See Marcus Peter Johnson, One with Christ: An Evangelical Theology of Salvation (Wheaton, IL: Crossway, 2013) 99–100. Jonathan Edwards, however, is unique in his choice to talk about how faith makes it fitting that God declares us just. For discussions of Edwards position, see Josh Moody, ed., Jonathan Edwards and Justification (Wheaton, IL: Crossway, 2012).
 Calvin, Institutes, 733. Wayne Grudem writes, “Scripture never says that we are justified because of the inherent goodness of our faith, as if our faith has merit before God. It never allows us to think that our faith in itself earns favor with God. Rather, Scripture says that we are justified “by means of” our faith, understanding faith to the instrument through which justification is given to us, but not at all an activity that earns us merit or favor with God” (Grudem, Systematic Theology, 730).
 Peter Martyr Vermigli writes that “we are said to be justified by [faith] because through it we take hold (apprehendimus) of the promises of God and the righteousness and merits of Christ, and apply them to ourselves” (Peter Martyr Vermigli, Locus on Justification, 96, quoted in Horton, Justification, vol. 2, 264–265).
 Belgic Confession, Article 22.
 WCF, 11.2
 John Owen, The Works of John Owen. 5: Faith and Its Evidences, ed. William H. Goold, 5. printing; Repr., Johnstone & Hunter, 1850-53. (Edinburgh: Banner of Truth Trust, 1998), 108–109.
 Horton, Justification, vol. 1, 263. Certainly, faith is a theological virtue. It is the duty of all men and women to trust in God’s Son (see Peter J Morden and Ian M Randall, Offering Christ to the World: Andrew Fuller (1754-1815) and the Revival of Eighteenth-Century Particular Baptist Life (Carlisle, Cumbria, U.K.; Waynesboro, GA: Paternoster, 2003)). In that respect, faith is a good thing. But the Reformed are careful to maintain that faith, though virtuous, does not justify because of its inherently virtuous character. Owen is clear when, in asserting faith as the instrumental cause of justification, he says faith is not “morally any way meritorious…nor has any other physical or moral respect to the effect of justification” (Owen, The Doctrine of Justification, 125).
 Calvin, Justification, loc. 1062.
 Belgic Confession, article 22.
 Socinianism is named after the teachings of Laelius and Faustus Socinius, two Italian theologians of the late 16th century. For detailed studies of Socinian doctrine, see H. J. McLachlan, Socinianism in Seventeenth-Century England (Oxford: Oxford University Press, 1951). For a more recent study see Sarah Mortimer, Reason and Religion in the English Revolution: The Challenge of Socinianism, Cambridge Studies in Early Modern British History (Cambridge, U.K. ; New York: Cambridge University Press, 2010). Also, Herman Bavinck, Reformed Dogmatics, trans. John Bolt and John Vriend, vol. 3 (Grand Rapids, MI: Baker Academic, 2003), 347–351.
 Stephen J. Wellum, “Behold the Lamb of God: Theology Proper and the Inseparability of Penal-Substitutionary Atonement from Forensic Justification and Imputation,” in Barrett, The Doctrine on Which the Church Stands or Falls, 364–376.
 Turretin, Justification, 73–74.
 Peter van Mastricht, Theoretical-Practical Theology, vol. 2, 18.
 John Owen notes the Socinian view in his work as well. He writes, “Concerning [justifying faith] and trust it is earnestly pleaded by many, that obedience is included in it. But as to the way and manner thereof they variously express themselves. Socinus and those who follow him absolutely, make obedience to be the essential form of faith, which is denied by Episcopius” (Owen, The Doctrine of Justification, 117). Thus, Owen understands the Socinians to link faith and obedience in ways that make obedience part of the root (rather than fruit) of justifying faith.
 Ibid., 19.
 For a discussion of the exegetical issues, see Harold W. Hoehner, Ephesians: An Exegetical Commentary (Grand Rapids, MI: Baker Academic, 2002), 342–343. According to Obrien, several early commentators believed “faith” was the antecedent of “gift” (e.g. Augustine). Obrien notes, however, ““This interpretation is grammatically possible,615 assuming that the term denotes ‘faith’ and not Christ’s ‘faithfulness’, and it is consistent with Pauline teaching elsewhere (cf. Phil. 1:29). However, the context demands that this be understood of salvation by grace as a whole, including the faith (or faithfulness) through which it is received” (Peter Thomas O’Brien, The Letter to the Ephesians, The Pillar New Testament Commentary (Leicester: Apollos, 1999), 289.
 John Calvin, Institutes of the Christian Religion, trans. John T McNeill (Louisville, KY: Westminster John Knox Press, 2006), 541.
 B. B. Warfield writes, “Protestant theologians have generally explained that faith includes in itself the three elements of notitia, assensus, fiducia…speaking broadly Protestant theologians have reckoned all these elements as embraced within the mental movement we call faith itself; and they have obviously been right in so doing.” Benjamin B. Warfield, The Works of Benjamin B. Warfield: Studies in Theology, vol. 9 (Grand Rapids, MI: Baker Book House, 2003), 340–41. In addition, Hermann Bavinck links these concepts to Melanchthon and the Lutheran tradition. See Herman Bavinck, Reformed Dogmatics: Holy Spirit, Church, and New Creation, vol. 4 (Grand Rapids, MI: Baker Academic, 2008), 113.
 Peter van Mastricht, Theoretical-Practical Theology, ed. Joel R. Beeke, trans. Todd M. Rester, vol. 2 (Grand Rapids, MI: Reformation Heritage Books, 2018), 7.
 Ibid., 8.
 According to Bavinck, the “various acts of faith are then again reduced to a number of classes, mainly three: the preceding acts (knowledge, theoretical assent, the humbling and denial of the self, and so forth); concomitant acts (practical assent, the yearning for Christ, taking refuge in Christ, apprehension of Christ, and so forth); the subsequent acts (vivifying, soothing, confirming, and fructifying grace)” (Bavinck, Reformed Dogmatics, vol. 4, 113). As is clear, then, the Reformed tradition has a complex understanding of the act of justifying faith. Therefore, including something like the affections, as we shall see, does not seem a stretch. Of course, whether or not the affections were part of the ontology of faith for the Reformed is something we have yet to prove.
 McGrath, Iustitia Dei, 206. It is important to note, however, that McGrath says “it is arguable that his translation of Paul’s term “justified” by the German phrase ‘gerecht werde (becomes righteous)’ rather than ‘gerechtfertigt’ is at least as significant, particularly given the trends towards declaratory approaches to justification which achieved dominance within Lutheranism during the 1530’s” (McGrath, 206–207). McGrath may be correct, yet the locus of the historical debate and the importance of his addition of “only” in Rom 3:18 is clear given the fact Trent addressed the issue and the historical debate that has ensued post-Reformation.
 Heiko Augustinus Oberman, Luther: Man between God and the Devil (New York, NY: Image Books, 1992).
 De Chirico, “Not by Faith Alone?”, 746.
 Ibid., 745–746.
 Calvin, Institutes, 748.
 Ibid., 749.
 Turretin, Justification, 86.
 Belgic Confession, 39.
 Horton, Justification, Vol. 2, 399.
 In advocating for justification sola fide, the Reformed tradition has also engaged with those who have argued that Reformed position inevitably leads to antinomianism. Roman Catholics leveled this charge and it has recurred for five-hundred years. Yet, for the Reformed, though justification is by grace alone through faith alone, that grace and faith are never alone. Calvin writes, “It is therefore faith alone which justifies, and yet the faith that justifies is not alone” (quoted in R. Lucas Stamps, “Faith Works: Properly Understanding the Relationship between Justification and Sanctification,” in Barrett, The Doctrine on Which the Church Stands or Falls, 520).