Joh 16:8 "And when He (the Holy Spirit) has come, He will convict the world of sin....
9 "of sin, because they do not believe in Me;
God the Father is the mastermind of salvation. God the Son paid the price of salvation. And God the Holy Spirit is the One who applies salvation. Here we are given one of the ministries of the Holy Spirit and the reason for it.
His Ministry
"He will convict the world of sin...."
He will strive with men (see Gen. 6:3) working in them to effect conviction of sin and repentance in their hearts. He will show men and women their helpless and hopeless condition with regards to saving themselves and point them to the sufficiency of the Savior. Sadly, many in the world resist Him.
The Reason
"He will convict the world of sin....of sin, because they do not believe (trust) in Me"
Apart from the ministry of the Holy Spirit no sinner by himself will come to realize his utter need of the Savior. He will never see the preciousness of the Cross of Christ and the necessity of trusting in Christ for salvation. And so the Holy Spirit comes to convict them because apart from His ministry, no one will trust in Christ.
Have you been convinced that sin is your greatest problem? Have you seen yourself a sinner totally unable to save yourself, hopeless and helpless in yourself in saving yourself and as a result, you came to Christ for salvation?
Many would teach that "conviction of sin" here specifically refers only to the sin of not trusting in Christ. And so, the Holy Spirit would come and specifically pin-point a particular sin in their lives---the sin of not trusting in Jesus."
I respectfully disagree. Look at the verse: ""He will convict the WORLD of sin". Obviously, not everybody in the world has heard about Christ and His salvation. That is why we still do evangelism today. Are we to imagine that the Holy Spirit would come and say to a native in the jungles of Africa who have never heard anything about Christ and say to him: "You do not trust in Christ, you are under judgment."
The native could respond: "Who is Christ by the way? I never heard of Him? Why are You charging me with that sin?"
Not everyone in the world has heard about Christ and His salvation. So the Holy Spirit could not indict them with something they do not know in the first place. But since everybody is a guilty sinner, since everybody has been given light by God (to some degree) which they have never kept faithfully and perfectly, then the Holy Spirit could convict them and indict them of being a sinner in need of a Savior.
Conviction of sin refers to the Holy Spirit showing us as to who we are in ourselves, that we are helpless and hopeless and in desperate need of a Savior.