Most translations use quotes around "the circumcision", (NIV, NASB, NRSV, HCBS). i.e. NIV:
Therefore, remember that formerly you who are Gentiles by birth and called “uncircumcised” by those who call themselves “the circumcision” (which is done in the body by human hands)
However ESV (and KJV) does not place quotes around "the circumcision":
Therefore remember that at one time you Gentiles in the flesh, called “the uncircumcision” by what is called the circumcision, which is made in the flesh by hands
In the former, "the circumcision" is referring to people, aka, "those who call themselves..." but in the latter, its not people "by what is called...."
While there is no significant theological issue dependent upon this difference, there is a subtle historical difference between the two options. So the question is, what is the evidence that supports the choice between the two? Historically speaking, can we determine if Paul is referring to:
- a group of religious people called "the circumcision", used the term "the uncircumcision", or
- a act/law/practice of circumcision created the concept of "the uncircumcision".