Though there is no perfect translation of the Bible, we have to work hard to make a more acceptable one, not by injecting our ideology or interest but by honoring the original syntax and experience of the people in and behind the text.
I often use Rom 3:22 and Gal 2:16 as a test case for judging the quality of translation. Below are CEB (the most recent translation), NRSV, NIV (new), and NIV (old). Generally speaking, CEB and NRSV are preferable to NIVs. Even CEB and NRSV have some problems.
CEB has a nice job in Rom 3:22 by translating pistis christou as "the faithfulness of Christ" and also dikaiosyne theou as "God's righteousness" (both of which are the subjective genitive cases). But unfortunately, in Gal 2:16 the same phrase pistis christou is translated as "faith in Christ" (the objective genitive). This means there is no consistency. Perhaps this is because of the influence by the doctrine of "justification by faith."
NRSV is similar to the CEB. The good thing in NRSV is that dikaiosyne theou is translated as "the righteousness of God," which allows room for interpretation (either as the subjective genitive or the objective genitive case). In other words, the reader has to decide which genitive case he or she will read. NIV (old) is not good.
Erga nomou is translated as "by observing the law," which is not found in the text; this translation is based on a clear theological interest. Literally, the phrase erga nomou means "the works of the law" whatever it means. Again, it is the reader's job that what the works of the law means in Paul's letter. NIV (new) has it now "the works of the law" like the NRSV. That is a small improvement. But both NIV (new) and NIV (old) have a strong tendency for securing the theological doctrine of "justification by faith." For example, in Rom 3:22, both versions emphasize an individual righteousness by faith in Jesus. But this reading does not reflect Paul's concerns and theology.
Syntactically speaking, CEB translates Rom 3:22 very well and is close to my interpretation about this verse. As I wrote in my book, A Theological Introduction to Paul's Letters (Cascade Books, 2011), Rom 3:22 presents a snapshot of Paul's theology lodged in three parties to effect the salvation of God: God, Christ, and people.
There are three aspects of God's righteousness, Christ's faith, and believers (followers of Jesus), who have the faith of Christ. Furthermore, "believing in Jesus" in Gal 2:16 does not mean that Jesus is the object of faith in the sense that the believer put a faith in Jesus. In fact, the preposition used there is eis, not en. Eis means "toward" or "into," a kind of movement, action, or participation.
Therefore, what is emphasized here is that we have believed into him (like participating in him). That is, we co-work and co-suffer with him. That is what the faith means. Jesus showed that faith, and we follow his faith for God's righteousness. This is what I mean the threefold theology of Paul. For more about this, see my book, A Theological Introduction to Paul's Letters: Exploring a Threefold Theology of Paul.
CEB (Common English Bible)
Rom 3:22: "God's righteousness comes through the faithfulness of Jesus Christ for all who have faith in him"
Gal 2:16: "However, we know that a person isn't made righteous by the works of the Law but rather by faith in Jesus Christ. We ourselves believed in Christ Jesus so that we could be made righteous by faith in Christ and not by the works of the Law -- because no one will be made righteous by the works of the Law"
Rom 3:22: "the righteousness of God through faith in Jesus Christ for all who believe"
Gal 2:16: "yet we know that a person is justified not by the works of the law but through faith in Jesus Christ. And we have come to believe in Christ Jesus, so that we might be justified by faith in Christ, and not by doing the works of the law, because no one will be justified by the works of the law"
Rom 3:22: "This righteousness is given through faith in Jesus Christ to all who believe"
Gal 2:16: "know that a person is not justified by the works of the law, but by
faith in Jesus Christ. So we, too, have put our faith in Christ Jesus
that we may be justified by faith in Christ and not by the works of the law, because by the works of the law no one will be justified"
Rom 3:22: "This righteousness from God comes through faith in Jesus Christ to all who believe"
Gal 2:16: "know that a man is not justified by observing the law, but by faith in Jesus Christ. So we, too, have put our faith in Christ Jesus that we may be justified by faith in Christ and not be observing the law, because by observing the law no one will be justified"