I was dialoguing with Glen Robinson on the translation of Galatians 2:16 under the post "By Faith Alone." I've spent a lot of time reflecting on this verse and actually have an article coming out this year with CBQ that ends with my understanding of it. I thought I might make this a commentary post.
1. We who are Jews by nature and not sinners from the Gentiles...
As the next statement makes clear, Paul is referring to "we Jewish believers" and although I don't think he is still telling us what he said to Peter, the "we" refers to people like him and Peter--Jewish believers.
Sinners from the Gentiles is not tongue in cheek. What is a sinner if not a law breaker and what other law would be in view other than the Jewish law. Clearly Gentiles don't keep the Jewish law, so sinners is quite literal here. Gentiles are clearly sinners. Paul plays out this idea in the whole of Romans 1:18-32--"Gentiles are sinners."
To some extent, we should think of Paul as starting out with common ground between him and Jewish believers like Peter. As we will see, however, he considers Peter's perspective to be incomplete because Peter only sees half of the equation. Paul will round out the argument when he gets to 2:17--we Jews, even Jewish believers, are sinners too. That is reminiscent to the progression of thought in Romans 2:1-3:20, namely, that Jews have sinned too. In fact, all [both Gentile and Jew] have sinned and lack the glory of God (Rom. 3:23).
2. since we know that a person is not justified...
Justification here is a legal term. The issue is on what basis a person might be considered righteous or "not guilty" in the divine court. Perhaps more to the point, the issue is on what basis a person might not face God's judgment. While the question is primarily a judicial question, its most crucial relevance pertains to the Day of Judgment and is thus eschatological.
I remain unconvinced of N. T. Wright's claim that it is also covenantal, meaning that a primary part of the meaning is whether or not a person is a member of the people of God and Israel in particular. Certainly Paul's language should be read as corporately as possible, rather than individualistically ("we" since "we" know "we" have placed faith...). But the Israel angle has not yet "clicked" for me. I don't see it.
3. ...since we know that a person is not justified on the basis of works of law except through the faith of Jesus Christ...
"Works of law" must certainly refer to works of the Jewish law. Paul is still stating common ground between himself, Peter, and other "conservative" Jewish believers. None of them, in fact no Jew at all, would claim that they deserved God's favor. They of course did believe that works of the law were an essential part of the equation, but all would have agreed with Paul that deeds of the law, apart from God's graciousness, did not earn God's acceptance of them.
"Works of law" might have had a strong connotation of the kinds of issues Jewish sects are notorious for debating. Rabbi so and so says that such and such makes the hand unclean, while so and so other rabbi says it doesn't. 4QMMT is a Dead Sea document in which, perhaps, the leader of one Jewish sect argues for his understanding of various temple issues to one of the Maccabean high priests. The title of this document is "some of the works of the law." Accordingly, Dunn argues that while "works of law" likely refers to any deed of the Jewish law, it probably had overtones of the elements in the Jewish law that distinguished Jew from Gentile.
The natural force of the word usually translated as "but" is more naturally translated "except" or "unless" (ei me). Since Paul is still laying out common ground between himself and Peter/conservative Jewish Christianity, this perspective is perfectly natural. Peter believes that the faithfulness of Jesus unto death (in other words, the atonement afforded through his death) is an essential element in justification before God. BUT, works of law are also an essential part of the equation for James and friends.
To take the phrase "faith of Jesus Christ" as a reference to the faithfulness of Jesus and in particular his faithful death is to take a particular position in a long and well documented debate. I personally became finally convinced when I came to a particular conclusion on the logic of 2 Cor. 4:13. That was the straw that tipped the scales for me. However, a more obvious argument is the similarity between Rom. 5:19 and 3:22. The parallel is striking, as pointed out by Luke Timothy Johnson:
"Just as through the disobedience of the one man many became sinners,
so also through the obedience of the one man many will become righteous"
"through the faith of Jesus Christ ... being justified [declared righteous]"
The faith of Jesus Christ here refers to his obedience to death (Phil. 2:8) and thus is a shorthand way of referring to Jesus' atoning death, the redemption provided through the atoning sacrifice God made through Jesus' blood.
4. We Jews ... since we know that a person is not justified by works of [Jewish] law except through the faith[ful death] of Jesus Christ, even we have put our faith in Messiah Jesus...
The novelty here for Paul is to point out that in fact Jewish believers have not only put their faith in God and what God has done through Jesus, they have in a sense put their faith in Jesus as Messiah. We are so programmed to think of faith in Christ that we miss that this is in fact the more unusual way of thinking of faith both for Paul and even moreso for other Jewish Christians. Rather, their faith was primarily in God and in what God had done through Jesus. Romans 4 is all about faith in God, not faith in Christ. And in 1 Thessalonians, in my view before Paul started getting really thick into these debates, he speaks of faith toward God (1 Thess. 1:8). God remains throughout Paul's writings, in my view, the primary object of faith.
But Paul certainly can also speak of placing faith in Christ, as this verse and other places where he uses the verb form pisteuo. We are prone to draw false distinctions between the verb "to believe" and the noun "faith" because they look different in English. But it is the same root: pisteuo (believe) and pistis (faith). To believe thus often means to have faith, although we have to be careful because these words have a range of meanings and should not be translated the same in every instance.
Hopefully everyone knows that the word Christ is the Greek translation of Messiah. Most of the time, the word lurks without Paul drawing much attention to it. But I think it has meaning for him (see, for example, Rom. 9:5) and I think the word order here in Gal. 2 means something. When referring to the faithfulness of Jesus, Messiah, Jesus comes first. But now that Paul speaks of putting faith in him, he puts Messiah first because it is primarily as Messiah, as Christ, that we place our faith in him.
5. ... we have put our faith in Christ Jesus in order that we might be justifed by faith of Christ and not by works of law...
I think Paul is having a little fun here. The expression "faith of Christ" is deliciously ambiguous, as the history of the scholarly debate shows. Is it faith in Christ or the faith of Christ? I think given the lead up it must be both, a clever double entendre. But I think that given his comment to faith in Christ that has just preceded, it has the upper hand. In other words, if I gave the tie to Richard Hays in 2:16a, I'm going to give it primarily to Dunn here in 2:16c.
So Paul sets up a contrast. The balance of the phrases with what are called "objective genitives" speaks against seeing Hays' interpretation here: faithfulness of Jesus and not doing the law. We are justified by trusting Christ and not by doing law. The principle of justification by faith will then play itself out throughout Paul's subsequent argument.
6. ...for by works of law no flesh will be justified.
Here Paul cites and modifies Psalm 143:2. The verse says that no one living is righteous before God. Paul changes "no one living" to "no flesh." Flesh is of course a characteristic category for Paul, as we have seen. "Flesh and blood cannot inherit the kingdom of God" (1 Cor. 15:50). The key is therefore to get out of the flesh ;-), which we can due through the Spirit (Rom. 8:8).
Paul also adds the phrase "works of law" to the quote. In this way again those living can be justified through faith of Christ, even if not by works of law. Just as a final parting blow, Paul's use of Scripture here is the death blow to fundamentalist and biblicist interpretation. As I've argued elsewhere, we cannot use Scripture as Paul if we do not see the Word of God as something bigger than the words of the text. Paul found the text in the Word of God, he did not find the Word of God in the text.
"We who are Jews by nature and not sinners from the Gentiles, since we know that a person is not justified by deeds of law except through the faithfulness of Jesus Christ, even we have placed our faith in Christ Jesus, so that we might be justified by faith in Christ and not deeds of law, for no flesh will be justified by deeds of law."