Albert Barnes Commentary John 16:8

"And he, when he is come, will convict the world in respect of sin, and of righteousness, and of judgment:" — John 16:8 (ASV)

He will reprove. The word translated reprove means commonly to demonstrate by argument, to prove, and to persuade anyone to do something by presenting reasons. It therefore also means to convince of anything, and particularly to convince of crime. This is its meaning here. He will convince or convict the world of sin. That is, he will so apply the truths of God to their own minds as to convince them by fair and sufficient arguments that they are sinners, and cause them to feel this. This is the nature of conviction always.

The world. Sinners. The men of the world. All people are by nature sinners, and the term the world may be applied to them all (John 1:10; John 12:31; 1 John 5:19).