Stephen Carlson has put up a good post on why the translation of σάρξ as anything other than “flesh” in Gal 3:3 is “weak tea.” Carlson observes that Paul is making a point concerning literal flesh—the foreskin—but many translations unfortunately treat Paul’s language as metaphoric, translating σάρξ as “human effort” or other related phrases.
I’ll repeat my comment from Carlson’s blog here: In addition to spoiling the vividness of Paul’s speech, these translations import additional theological problems into the passage. I find no evidence anywhere in the letters that Paul has any issues with “human effort”; sure, he wants these efforts in conformity with χάρις, but he even points to his own efforts at times as an example of how to live. These translations import an a works/grace dichotomy that Paul doesn’t hold. As you know, the distinction is between works of Law and Grace as entrance points to righteousness, not suggesting all human effort is bad. It’s unfortunate that by their translation of σάρξ here, Paul’s overarching theme is badly distorted. Some of these minor translation bugs are bigger theological problems than many want to admit.
There’s a pretty good string of comments going as well; it’s well worth the brief read.