CLAIM: Greek grammarians debate whether or not this passage should be rendered as “faith in Jesus Christ” or “the faithfulness of Jesus Christ.” The first rendering is the objective genitive (“faith in”), while the second rendering is the subjective genitive (“faithfulness of”). Which is it?
RESPONSE: While many commentators make a big deal about this, it doesn’t significantly affect our understanding of this passage. Both translations affirm that all people come to Christ based on grace, through faith, and apart from works. That being said, we favor the objective genitive (“faith in Jesus”), rather than the subjective genitive (“the faithfulness of Jesus”) for a number of reasons:
First, the linguistic argument (for a subjective genitive) is not overwhelming. Of course, it’s true that we could translate this with the subjective genitive as the NET does (cf. Rom. 3:3; 5:19). However, many genitives in the NT are objective—especially when referring to God the Father or to Jesus (Mk. 11:22; Acts 3:16; Jas. 2:1; Rev. 2:13; 14:12; Col. 2:12; Phil. 1:27; 2 Thess. 2:13). Therefore, Moo writes that only “context… can determine the force of the genitive.”
Second, pistis in Paul “almost always means ‘faith.’” We would need very strong contextual clues to render this as “faithfulness” (as in Romans 3:3). Note that in Romans 4:12 and 4:16, the same expression is used but it refers to Abraham’s “faith,” rather than his “faithfulness.”
Third, in this section of Romans (3:21-4:25), pistis consistently refers to faith in God or Christ. In this section, Osborne notes that “faith speaks of belief in Christ (seventeen times!).” Later, verses 28 and 30 simply refer to “faith,” which presupposes “faith in Christ.”
OBJECTION: Isn’t it redundant for Paul to write “faith in Jesus Christ” and then write “for all those who believe”?
In our estimation, this is the strongest argument in favor of a subjective genitive. However, even this isn’t compelling. This repetition shows that “God’s righteousness is available only through faith in Christ—but it is available to anyone who has faith in Christ.” That is, the first statement refers to the instrument of salvation (“faith”) and the second statement refers to the people who receive salvation (“those who believe”). Since Paul has been emphasizing both the sinfulness of Gentiles and Jews, it would only make sense for him to emphasize the universal invitation of God’s forgiveness (“for all those who believe”).
 See footnote. Douglas J. Moo, The Epistle to the Romans, The New International Commentary on the New Testament (Grand Rapids, MI: Wm. B. Eerdmans Publishing Co., 1996), 225.
 Douglas J. Moo, The Epistle to the Romans, The New International Commentary on the New Testament (Grand Rapids, MI: Wm. B. Eerdmans Publishing Co., 1996), 225.
 Grant R. Osborne, Romans, The IVP New Testament Commentary Series (Downers Grove, IL: InterVarsity Press, 2004), 94.
 Douglas J. Moo, The Epistle to the Romans, The New International Commentary on the New Testament (Grand Rapids, MI: Wm. B. Eerdmans Publishing Co., 1996), 226.