“In its condemning power, the law is very different from the gospel. The law condemns, and cannot justify a sinner: the gospel justifies, and cannot condemn the sinner who believes in Jesus.
In the law, God appears in terrible threatenings of eternal death; in the gospel, He manifests Himself in gracious promises of life eternal.
In the former, He curses as on Mount Ebal; in the latter, He blesses as on Mount Gerizzim. In the one, He speaks in thunder and with terrible majesty; in the other, with soft whispers or a still small voice (1 Kings 19:12).
By the trumpet of the law, He proclaims war with sinners; by the jubilee-trumpet of the gospel, He publishes peace, ‘peace on earth and good will toward men’ (Luke 2:14). The law is a sound of terror to convinced sinners; the gospel is a joyful sound, ‘good tidings of great joy.’
The former represents God as a God of wrath and vengeance; the latter as a God of love, grace, and mercy. The one presents Him to sinners as ‘as consuming fire’; the other exhibits the precious blood of the Lamb which quenches the fire of His righteous indignation so that it may not consume such sinners as believe. That presents to the view of the sinner a throne of judgment, this is a throne of grace.
Every sentence of condemnation in Scripture belongs to the law; every sentence of justification forms a part of the gospel. The law condemns a sinner for his first offense, but the gospel offers him the forgiveness of all his offenses.”
John Colquhoun, A Treatise On The Law And The Gospel, pp. 150-151.