Here "the earth" is used to represent the people on the earth. Alternate translation: "The people of the world are" (See: [[rc://en/ta/man/translate/figs-metonymy]])
This idiom means God keeps the judges of the earth from being able to judge the difference between right and wrong. Alternate translation: "God makes its judges blind" or "God keeps its judges from judging rightly" (See: [[rc://en/ta/man/translate/figs-idiom]])