Thomas Manton (Works, vol. 4, p. 104):
[W]hat reason we have to mortify sin lest it mortify us; no sins are mortal but such as are not mortified; either sin must die, or the sinner. The life of sin and the life of a sinner are like two buckets in a well—if the one goeth up the other must come down. When sin liveth the sinner must die. There is an evil in sin and an evil after sin. The evil in sin is the violation of God’s law, and the evil after sin is the just punishment of it. Now, those that are not sensible of the evil in sin shall be sensible of the evil after sin. To the regenerate person, all God’s dispensations are to save the person and destroy the sin, Ps. 99:8: ‘Thou wast a God that forgavest them, and tookest vengeance of their inventions.’ God spared the sinner and took vengeance on the sin; but the unmortified person spareth his sins, and his life goeth for it; as the apostle Paul speaketh of himself when the power of the word came first upon him, Rom 7:9, ‘Sin revived and I died.’ Sin was exasperated, and he felt nothing but terror and condemnation. Oh! then, consider it is better sin should be condemned than you should be condemned; as the apostle speaketh of the condemnation of sin, Rom. 8:3, ‘For sin, he condemned sin in the flesh;’ that is, Christ being made a sacrifice for sin, sin was condemned to save the sinner. Reason thus within yourselves: It is better sin should die than I should die: ‘Thy life goes for its life,’ as it is in the prophet’s parable, 1 Kings 20:39; therefore let me destroy my sin, that my soul may escape.