Question: What does phrase "reprove the world of sin" mean (John 16:8)? This verse (kjv) says: "And when he is come, he will reprove the world of sin, and of righteousness, and of judgment." It is part of a long discourse in which Jesus was talking to His twelve apostles to whom He would send the Holy Spirit, the Comforter, who would guide them into all truth (John 14:26; 16:13; etc.). On the next day of Pentecost, the Holy Spirit came upon the twelve apostles (Acts 2:1-3) in the fulfillment of Christ's promise to them that they would "be baptized with the Holy Ghost not many days hence" (Acts 1:5). Being filled with the Holy Spirit the apostles were inspired, along with the prophets upon whom the apostles had laid their hands (Acts 8:14-17), to preach and write the New Testament. The Holy Spirit, as one of the three members of the "Godhead" (Acts 17:29; Matt. 28:19), inspired the apostle, John, to write the words: "he will reprove the world of sin..." When Jesus used the word "he" in this verse, He was referring to the Holy Spirit, so the Holy Spirit reproves the world by means of the New Testament which He inspired the apostles and prophets to write.    

        The word "reprove" means to expose, convict, rebuke, convince (Vine). This definition can be seen in its usage in John 3:20,21: "For everyone that doeth evil hateth the light, neither cometh to the light, lest his deeds be reproved. But he that doeth truth cometh to the light, that his deeds may be manifest, that they are wrought of God."  Here the word "reproved" has the idea "to shed light upon", and some translations have the word "exposed" here.  The Holy Spirit reproves the world of sin, by the written, inspired word of God when we read and study it. In the Bible we can learn what sin is (1 John 3:4; 5:17; James 4:17), who has sinned (Rom 3:23), and what the consequences of sin are (Rom. 6:23; 1 Cor, 6:9,10; Rev. 21:8).  "But if you show partiality, you are committing sin, and are convicted by the law as transgressors" (James 2:9, nasb). "Preach the word; be instant in season, out of season; reprove, rebuke exhort with all longsuffering and doctrine, for the time will come when they will not endure sound doctrine; but after their own lusts shall they heap to themselves teachers, having itching ears." (2 Tim. 4:2). Jesus told the church at Laodicea: "As many as I love I rebuke and chasten: be zealous therefore and repent" (Rev. 3:19). Come study with us any time.