The imperative form Let no one is not commonly used in English and some other languages. Good News Bible‘s “No one should” is better modern English. Translators need to find the best way to render imperatives in their languages rather than following an English model literally. As in previous verses, Good News Bible uses “you” forms in order to avoid masculine language, but “you yourself” does not refer to any individual. New Revised Standard Version has “Do not deceive yourselves. If you think that you are wise in this age, you should become fools so that you may become wise.”
Good News Bible‘s “fool himself” is a good common language rendering that equals Revised Standard Version‘s deceive. The phrase has nothing to do with the terms for “folly” or “madness” that Paul uses in other places. Other possible translations are “delude” or “be under any illusion” (Phillips).
The punctuation of the next part of the sentence is uncertain. All translations consulted appear to agree with Good News Bible and Revised Standard Version. Westcott and Hort’s Greek New Testament, which some commentators follow, makes a balanced sentence such as is often found in the writings of Paul (see verses 4-5) and other biblical writers.
This links among you with wise, giving the meaning “If anyone thinks he is wise by the standards of your group,” just as in the following clause “in this world” means “by this world’s standards” (Good News Bible). If this argument is correct, a possible alternative to Revised Standard Version and Good News Bible would be “Anyone who thinks he is wiser than the rest of you should become a fool by this world’s standards.”
As in verses 12-15, the If almost certainly implies that some people in Corinth did “think they were wise,” so one may translate the clause If any one among you thinks that he is wise, as “Anyone who thinks he is wise…,” or “Any person who thinks….”
On wise, see comments on 1.5, 19.
For a discussion of the word translated age, see the comment on 2.6. “World” (Good News Bible) is a better translation here.
The word for fool was often used by followers of popular teachers in the ancient world to refer to people outside their group, or to nonthinkers generally. The contrast in this verse is with the kind of philosophical speculation that some people at Corinth seem to have called “wisdom.” “Madman” is therefore too strong a translation here. Paul does not use the words for fool and “folly” (verse 19) outside this part of 1 Corinthians.
Good News Bible‘s “really” is not in the Greek, but is necessary in good English to bring out the contrast with “by this world’s standards,” and to prepare for verse 19.
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 .