Profound Sense of Need

When [the Holy Spirit] comes, he will prove that world to be in the wrong about sin...
about sin, because people do not believe in me.
John 16. 8,9

Moody:

Note that Jesus does not say here that the role of the Spirit is to give faith (though see Ephesians 2:8), but to convict of sin where there is no faith. Faith, then, is a response to a profound sense of need. Faith is not merely an intellectual appropriation of truth. It is also, and more foundationally, a trusting cry to Jesus to be saved. A man on dry land may in a certain sense believe in a lifeboat. But he does not trust his life to a lifeboat until he finds himself drowning at sea. Similarly, we need to be convicted of sin before we will savingly trust in Jesus.

We are all sinners; as the Anglican prayer book says, there is no health in us. Of course, many people do not think like that. They do not think there is anything seriously wrong with them. But when the Spirit works powerfully, he convinces people that there is a righteous standard before which they fall short. All false religions begin from the premise that there is not too much wrong with us and therefore for us to be saved only requires a list of rules or rituals to obey. Christianity begins from the premise that humanity is by nature destitute, blind, naked, deaf, and utterly dead in sin. It is the work of the Spirit, for which we must pray, to take our words and our lives and convince the world of the reality of their deadness before a holy God, that they might cry out to Christ to be saved.