Joel Beeke
The Puritans, then, were not afraid to use the law of God as an instrument of evangelism. When God is about to play the chord of grace in the soul, they taught, he usually starts with the bass note of the law.

And even if our gospel is veiled, it is veiled to those who are perishing. In their case the god of this world has blinded the minds of the unbelievers, to keep them from seeing the light of the gospel of the glory of Christ, who is the image of God.
2 Corinthians 4:3-4