Scripture clearly affirms the doctrine of justification by faith, what then is the precise relationship of faith to justification? The answer lies in what is entailed in the preposition “by”. “Few things are more necessary for a correct understanding of the New Testament,” wrote J. Gresham Machen, “than a precise acquaintance with the common prepositions.”
6 The New Testament writers commonly employ three expressions: piste, ek pisteos, and dia pisteos. The Christian is justified “by faith” (pistei or ek pisteous) or “through faith” (dia pisteos).
For example, pistei (the dative case of the noun pistis) is used in Romans 3:28: “Therefore we conclude that a man is justified by faith without the deeds of the law.”
Ek pisteos is used in Romans 5**“Therefore being justified by faith, we have peace with God through our Lord Jesus Christ.”** Dia pisteos is used in Ephesians 2:8 “For by grace are ye saved through faith; and that not of yourselves: it is the gift of God” (emphasis added).
Each of these three usages has its own special emphasis or significance. The use of the simple dative (pistei) calls attention to the necessity and importance of faith. The use of the preposition dia (“through” or “by means of”) describes faith as the instrument of justification, i.e., the means by which the righteousness of Christ is received and appropriated by the sinner unto justification. The use of the preposition ek (“from,” “out of,” or “by”) describes faith as the occasion of justification, though never as the efficient or ultimate cause of justification. 7
It is critical to note that in none of these cases, nor anywhere else in Scripture, is faith (or any other grace) represented as constituting some ground of merit for justification.
And this is all the more remarkable when one considers that dia with the accusative would mean “on the ground of” or “on account of.” Thus, dia ten pistin would convey the notion of “on the ground of or on account of faith,” thereby making faith the meritorious reason for the believer’s acceptance with God.
Yet such is the precision of the Spirit’s oversight of the New Testament scriptures that nowhere does any writer ever slip into using this prepositional phrase. On every occasion faith is presented as the means of justification.
Justification by faith alone is never justification on account of faith (propter fidem), but always justification on account of Christ (propter Christum), i.e. on account of the blood-satisfaction of the Lamb of God being graciously imputed to and received by an undeserving sinner (Galatians 3:6; James 2:23). Ultimately, the ground of justification is Christ and His righteousness alone. 8
In the Reformed tradition, various theological terms of expressions have been used to capture this biblical relationship of faith to justification.
For example, the Belgic Confession of Faith (1561, Article 22) and the Westminster Confession of Faith (1647, Chapter 11.2) denominate faith as “only an instrument” and “the alone instrument of justification.”
9 Faith is not an agent (i.e. an efficient cause), but an instrument (i.e. a means) of justification. It is the believer’s sole means by which he receives justification this means is not mechanical as the word “instrument” unfortunately implies; rather, this means is itself the saving work of the Holy Spirit through the Word whereby a sinner is brought into a living, personal relationship with the triune God.
The Heidelberg Catechism (1563, Question 61) states that there is "no other way (nicht anders) than faith by which Christ’s righteousness becomes ours. God did not ordain faith to be the instrument of justification because of some peculiar virtue in faith, but because faith is self-emptying and has no merit in itself: “Therefore it is of faith, that it might be by grace” (Romans 4:16).
John Calvin compares faith to an empty vessel: “We compare faith to a kind of vessel; for unless we come empty and with the mouth of our souls open to seek Christ’s grace, we are not capable of receiving Christ.” 10 The vessel cannot be compared in value to the treasure it contains (2 Corinthians 4:7).
The Puritan Thomas Goodwin uses strong and active language: “Faith is eyes, and hands, and feet, yea, and mouth, and stomach, and all.” 11 And the nineteenth-century Bishop J. C. Ryle writes: “Saving faith is the hand…the eye…the mouth…and the foot of the would.”
12 Yet faith lives by the Living Bread alone, not by the mouth that fees on the bread (John 6:35-58).
The sinner is justified by Christ’s sacrifice alone, not by his act of feasting upon or believing in that sacrifice by faith.
Second, is it accurate to call faith “a condition of justification,” as has frequently been done?
Given the meaning of “by faith” in the original Greek, it is more accurate to speak of faith as an instrument rather than a condition of justification and salvation, for a condition generally denotes a meritorious quality for the sake of which a benefit is conferred.
We are justified not merely by faith, but by faith in Christ; not because of what faith is, but because of what faith lays hold of and receives. We are not saved for believing but by believing.
In the application of justification, faith is not a builder but a beholder; it has nothing to give or achieve, but has all to receive. Faith is neither the ground nor substance of our justification, but the hand, the instrument, the vessel which receives the divine gift proffered to us in the gospel.
“As little as a beggar, who puts forth his hand to receive a piece of brad, can say that he has earned the gift granted him,” Herman Kuiper wrote, “so little can believers claim that they have merited justification, just because they have embraced the righteousness of Christ, graciously offered them in the Gospel.”
J.