Is the book of Job inspired of God? It makes no direct claim of inspiration. How, therefore, is one to know? One factor is the manner in which the book is treated by inspired writers of the New Testament.
Paul acknowledges the divine origin of this ancient document in 1 Corinthians 3:19 when he pens these words: "For it is written, He that takes the wise in their craftiness. . . " The expression, “it is written,” translates the Greek term gegraptai, a perfect tense, passive voice form, literally meaning, “it has been written and stands so.” The term, and several equivalent forms, are used in the New Testament for inspired writings. The expression is a technical one used to identify the “sacred books of the Old Testament” (J.H. Thayer, Greek Lexicon, p. 121). Mark Job 5:13 and in your margin note: See 1 Corinthians 3:19; Job identified as scripture. Paul also borrows a passage from Job in Romans 11:35.