If any one: it is not necessary to suppose that the person(s) referred to are outside the group that Paul described as “all of us” in verse 1. Paul is here exploring more deeply what is meant by “knowledge.” Good News Bible uses plural forms (“they”) in order to avoid masculine pronouns, thereby losing Paul’s tactful If. In fact, Paul knew that there were members of the church in Corinth who claimed secret knowledge. New Revised Standard Version repeats “anyone” in verse 3.

This verse distinguishes between (a) the state of knowing something or having acquired a piece of knowledge (verse 2a), and (b) the event of acquiring knowledge (verse 2b). A possible translation is the following: “If a person thinks that he has attained to some degree of knowledge, he has not yet reached the stage when he has any knowledge at all in the real sense of the word.”

Quoted with permission from Ellingworth, Paul and Hatton, Howard A. A Handbook on Paul’s First Letter to the Corinthians, 2nd edition. (UBS Handbook Series). New York: UBS, 1985/1994. For this and other handbooks for translators see here .