Nevertheless I tell you the truth; It is expedient for you that I go away: for if I go not away, the Comforter will not come unto you; but if I depart, I will send him unto you. And when he is come, he will reprove the world of sin, and of righteousness, and of judgment: of sin, because they believe not on me; of righteousness, because I go to my Father, and ye see me no more; of judgment, because the prince of this world is judged. John 16:7-11
The Comforter:
1. reproves the world of sin because they believe not on Jesus (see Hebrews 3:12)
2. reproves believers of righteousness because Jesus is at the right hand of the Father and we (believers) see Him (physically) no more
3. reproves the devil of judgement because the prince of this world is judged