1 Corinthians 15:14,17
And if Christ has not been raised, then our preaching is in vain and your faith is in vain. And if Christ has not been raised, your faith is futile and you are still in your sins.

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.
Joel Beeke