The sermon emphasizes that true salvation is exclusively the work of God, where the Holy Spirit directly teaches and convinces sinners of their depraved state. It argues against human-centered methods of conversion, asserting that individuals are spiritually dead and unable to seek God without divine intervention. The message highlights God's eternal election and sovereignty in choosing who will be saved, independent of human merit or effort. By revealing the awfulness of sin and hell, the Spirit causes the sinner to know his inability and his need of Christ, ensuring that the saved sinner knows their redemption is entirely God's doing. This divine teaching brings assurance of salvation, distinguishing it from mere intellectual knowledge or emotional responses.