8 And when he is come, he will reprove the world of sin, and of righteousness, and of judgment:

9 Of sin, because they believe not on me;

10 Of righteousness, because I go to my Father, and ye see me no more;

11 Of judgment, because the prince of this world is judged.

Spencer W. Kimball

The Holy Ghost can play an important role in convincing the sinner of his error. He helps in making known "the truth of all things" (Moro. 10:5); in teaching all things and bringing all things to one's remembrance (John 14:26); and in reproving the world of sin (John 16:8). [The Miracle of Forgiveness, p.152]

Bruce R. McConkie

Men are convicted of sin when they reject the Spirit-borne witness that Jesus is the Christ. They are convicted for rejecting the witness that he is righteous and that righteousness comes by him. They are convicted of false judgment in rejecting the Lord of life and living instead after the manner of the world. Thus saith the Lord: "Behold, I send you out to reprove the world of all their unrighteous deeds, and to teach them of a judgment which is to come." (D&C 84:87.) Truly, the Holy Ghost, by the mouths of the Lord's agents, reproves the world for sin! (A New Witness for the Articles of Faith, p.273)