I know that we would say that faith is an instrument whereby we receive Christ’s imputed righteousness, but is there some biblical or theological reason why we would not want to say that faith is also a virtue? Can’t faith be a virtue and an instrument? Or is there something about faith being a virtue that would undermine the Protestant doctrine of justification?
In the middle ages and in Roman theology today was and is common to speak of faith as one of the three theological virtues (along with hope and love). That approach created problems. Along with hope (spes) and love (caritas) the virtue of faith became (and remains for Rome and for moralists) its Spirit wrong, sanctifying power. In other words, historically to speak of faith or hope or love as a “virtue” in this way has been to locate the power of faith in faith itself or in the effects of faith.
The English noun “virtue” is derived from the Latin noun “virtus,” the root sense of which is “strength” or “power.” To speak of faith “as a virtue” tends to cause folk to locate the power of faith in faith itself.
The WCF uses the word “virtue” with the sense of “power” or “strength” in 8.6:
Although the work of redemption was not actually wrought by Christ till after his incarnation, yet the virtue, efficacy, and benefits thereof were communicated unto the elect….
WCF 13.1 speaks of the “virtue of Christ’s death.” 14.2 uses the expression “by virtue of the covenant of grace.” 30.1 speaks of the “virtue” of the keys of the kingdom. Of the Reformed confessions, the Second Helvetic Confession (1561/1566) uses the noun “virtue” in the same way. Chapter 10 explicitly denies that we were called or elected because of any virtue inherent in us (2 Tim 1:9). In chapters 14 and 16 we are exhorted to strive toward virtue as a consequence of our redemption.
2 Peter 1:5 is to the point here:
For this very reason, make every effort to supplement your faith with virtue (αρετη), and virtue with knowledge….
Given this sense of of “virtue,” as “strength” or “moral excellence”) neither the Three Forms nor the Westminster Standards speak of faith as a “virtue.”
In contrast to the medieval and Roman Church, Protestants think that Christ is the virtue of faith (WCF 13.1). It was the Remonstrant/Arminian move back to toward the medieval conception of faith as virtue with intrinsic qualities that concerned the Reformed Churches.
Notice how how WCF 14.1 characterizes of saving faith:
The grace of faith, whereby the elect are enabled to believe to the saving of their souls, is the work of the Spirit of Christ in their hearts, and is ordinarily wrought by the ministry of the Word, by which also, and by the administration of the sacraments, and prayer, it is increased and strengthened.
We may speak of the virtue of faith but only if we finish it by saying “is Christ.” He must be the virtue of faith because he is the object of faith. There is nothing intrinsic to faith that makes it powerful. The mystery of faith is that it is, in itself, empty. It is a sign of our perversity that we continually try to fill faith with something other than “Christ for us.” We want to make the power of faith to be faith itself or Spirit-wrought sanctity or something else beside Christ.
The Westminster Divines (with all the Reformed Churches) were acutely aware of this tendency. Thus they defined faith, in the act of justification, very carefully in order to preclude this very thing:
Those whom God effectually calleth, he also freely justifieth: not by infusing righteousness into them, but by pardoning their sins, and by accounting and accepting their persons as righteous; not for anything wrought in them, or done by them, but for Christ’s sake alone; nor by imputing faith itself, the act of believing, or any other evangelical obedience to them, as their righteousness; but by imputing the obedience and satisfaction of Christ unto them, they receiving and resting on him and his righteousness, by faith; which faith they have not of themselves, it is the gift of God.
Faith does not justify because it is “formed by love,” i.e. made powerful by Spirit-wrought sanctity and/or cooperation with grace. It is “ever accompanied” (11.2) by other “saving graces” but these other saving graces do not make faith what it is. Contra the rationalists and moralists faith is made powerful by being intrinsically powerless. I highlighted in the quotation from 11.1 above the expression. “nor by imputing faith itself….” This is the Remonstrant error. It is not faith itself that is imputed. It is Christ’s active and passive obedience that is imputed to us. Faith, as the divines remind, rests and receives. As the Belgic says, it “leans.” It isn’t even the act of believing itself.
Christ and nothing else is the virtue of faith.