Romans 5:1 in NRSV, NIV, and NEV all use the phrase, "since we are justified by faith," or we "have been justified by faith." In the CEB, though, the phrase reads, "since we have been made righteous through his faithfulness." I want to use Romans 5 in conjuction with Genesis 18 and Sarah's story, so the wording in Romans makes a huge difference, at least in my mind. Is there a good reason the CEB translates the Greek differently?
There's really not a good reason for the CEB's translation, in my opinion. The grammar and vocabulary of the opening clause in Rom 5:1 is pretty straightforward. What's under debate among interpreters is what Paul means by the verb dikaioō (traditionally translated as "justified") and the noun pistis (traditionally translated as "faith") in this context and more broadly throughout Romans. The CEB translation committee thought that "made righteous" is more appropriate than "justified." Maybe they wanted readers to know that the Greek word there is related to the noun dikaiosunē (typically translated as "righteousness"). I worry that neither "justified" nor "made righteous" means much to modern English speakers, but translators needed to choose something. As for the rest of the clause, there is no Greek word for "his" in this clause. Instead, Paul speaks merely of "faith" (although "faithfulness" is another possible rendering of pistis). The addition of "his" (meaning, Jesus') is probably because the CEB translation committee was persuaded that Paul is talking about Jesus' own faith[fulness] as the thing that brings about humanity's being made right before God and with God. Although there's good reason to come to that conclusion, in light of Paul's overall argument and his ways of speaking about pistis, I think that translating it in that way takes that interpretive decision away from the reader.