In the NPP, if Paul's "works of the law" are only circumcision and diet, how is Galatians 3:10 interpreted? One of the implications of the New Perspective on Paul (NPP), as I understand it, is that Paul's teachings regarding the "works of the law" (in Galatians 2:16, for example) are meant to refer only to "boundary marker" laws, that is, laws like circumcision, diet, and calendar, as opposed to all of God's law.

This can have a significant impact on one's doctrine of justification, as it opens the door for other "works" (besides circumcision, etc.) to be part of the basis of one's salvation.

One challenge to this aspect of the NPP that I've seen is based on other references to the "works of the law" in Paul's writings, where he uses the same phrase but appears to be referring to the entire law.  For example, Romans 3:20:


  For by works of the law no human being will be justified in his sight, since through the law comes knowledge of sin. (ESV)


Here, critics of the NPP say, Paul is clearly referring to the entire law, not just "boundary marker" laws, since elsewhere he recognizes many other sins besides failure to circumcise.  But to me an even stronger passage appears to be Galatians 3:10:


  For all who rely on works of the law are under a curse; for it is written, “Cursed be everyone who does not abide by all things written in the Book of the Law, and do them.” (ESV)


Here, quoting Leviticus 18:5, Paul's use of "all things written in the Book of the Law," as opposed to some, is seen as plain evidence that "works of the law" to him means more than just circumcision, etc.

Thus, the question: 

How do proponents of the New Perspective on Paul respond to challenges to their view of Paul's "works of the law" that are based on Galatians 3:10 and similar passages?
It's interesting that this perspective is known as the the 'New Perspective on Paul', for the idea that works goes hand in hand with faith has been central to the Catholic and Orthodox Church which preceded the Reformed Church and its claim of sola fide. If you were to go to a Catholic or Orthodox Christian in the 12th century and claim that St. Paul thought that faith meant the eradication of good works in the process of salvation, you might have very well been burned at the stake for heresy. 

As to Galations 3:10, it is important for us to not 'cherry-pick' verses (even John 3:16) out of their context in order to support a position. It should thus be noted that Paul's inclusion of the verse from Leviticus might be used in a way that is contrary to what the writers of Leviticus were referring to. It should also be noted that the term 'law' is itself requiring contextual analysis in order to derive its actual meaning as intended by Paul (it does not 'instinctively' mean anything). With that said, we should now look at the surrounding context of Galatians to consider what Paul even means when he refers to the 'curse of the law'.

Galations 3:15-18


  Brothers and sisters, I give an example from daily life: once a person's will has been ratified, no one adds to it or annuls it. Now the promises were made to Abraham and to his offspring: it does not say. 'And to offsprings', as of many; but it says, 'And to your offspring', that is, to one person, who is Christ. My point is this: the law, which came four hundred years later, does not annul a covenant previously ratified by God, so as to nullify the promise. For if the inheritance comes from the law, it no longer comes from the promise; but God granted it to Abraham through the promise.


The surrounding context in reference to the 'curse of the law' is rather clearly in a 'covenant language'. Even following this passage Paul continues to write how baptism is in essence the 'new circumcision'. N.T Wright would say Paul's speaking about 'badges of covenant membership'. The universal essence of 'doing good' and its relation to salvation for humanity, in other words, is not necessarily being spoken about by Paul. Rather, when Paul speaks of the 'law' he is more precisely speaking about the way the Jewish customs relate to an understanding of God's covenant. 'Law' in other words is referring to the things of temporary power and purpose (such as circumcision, observance of certain days, etc). Paul himself later asserts this understanding of the 'law' as a temporary power in saying that it 'was added because of transgressions, until the offspring would come to whom the promise had been made'. Good deeds in no way are a 'temporary' matter, and for Paul to believe such would be to contradict clear statements by Jesus and other apostles all throughout the rest of the New Testament, who vouch for the understanding that 'wisdom is justified by her deeds' and that a 'tree is known by its fruit'. Stating that good deeds are temporary in a justifying nature would even diminish the very good deed Christ did on the cross. 

It should also be said that NPP does not support the idea that good deeds alone can attain salvation. Good deeds are supplementary to faith. The one cannot exist without the other, for they justify each other. The language regarding each one thus does not exclude the language regarding the other, for the language of both is typically one in the same.

The NPP isn't really all that 'new'. It's been around in traditional Christian language since the beginning as an assumption that might very have been taken advantage of by its proponents. But the Reformed thought that has stressed sola fide has produced some good by forcing those who support the idea that good deeds must accompany faith to look back into the bible with a new set of eyes. What the bible says is still a resounding 'no' to sola fide.