Salvation does not come by anything the natural man can do. A person cannot be saved by repeating a prayer,by walking a church aisle, by making a decision, or by being baptized and joining the church. Salvation comes to helpless, dead sinners only by the mighty, effectual operations of God the Holy Spirit. Salvation is the result of Holy Spirit conviction. Our Lord Jesus declares that when the Spirit of God comes in saving grace to a sinner he will convince that person "of sin, because they believe not on me." Martin Luther wrote, "The recognition of sin is the beginning of salvation." But that recognition of sin is much more than just the recognition that you have committed a sin, or a number of sins. It is a recognition of your nature, your inward corruption and depravity. When the Spirit of God convicts a person of his sin the convicted sinner is graciously forced to see and acknowledge his guilt before the holy God (Psa. 51:3-5). And he sees that he is utterly without ability to change his nature.
I know that the whole world has sinned and is guilty before God. But the Lord God has graciously shown me that I am guilty, deserving of his wrath, and without excuse before him. The evidence is all in. It is irrefutable. I am convinced. I am guilty. From the depths of my filthy soul I cry, "God be merciful to me, the sinner!" This conviction is contrary to nature. It is the work of God the Holy Spirit.
The specific issue of conviction is unbelief. All men know by nature that such things as robbery,adultery and murder are sin.But it is a supernatural work of God the Holy Spirit that convinces us that unbelief is sin. Indeed, unbelief is the greatest of all sins, and the most damning. Unbelief is the heart of man declaring that God is a liar (I John 5:10)! Every sin is damning. But no sin is damning to the unbeliever.The heathen are lost for want of knowledge. But those who upon hearing the gospel refuse to believe on the Lord Jesus Christ are lost for want of faith, by their wilful, obstinate unbelief.So their unbelief shall be their condemnation. It is unbelief that keeps them from entering into rest. Unbelief deserves and shall have the unmitigated, everlasting wrath of almighty God in hell. Blessed is the man or woman who by the Spirit of God is convicted of sin and turned from unbelief to faith in Christ!