en_tn/1co/03/18.md

Let no one deceive himself

Nobody should believe the lie that he himself is wise in this world.

in this age

according to the way people who do not believe decide what is wise

let him become a "fool"

"that person should be willing to have people who do not believe call him a fool" (See: rc://en/ta/man/translate/figs-irony)