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.

For the word of the cross is folly to those who are perishing, but to us who are being saved it is the power of God.
1 Corinthians 1:18