Surah 78. An-Naba, Ayah 30

Lit., "We shall not increase you in anything but suffering": i.e., until the sins committed in this world are atoned for by commensurate suffering in the hereafter - for "whoever shall come [before God] with an evil deed will be requited with no more than the like thereof; and none shall be wronged" 6:160 .

Just as there is a progressive deterioration in the sinner's soul when he surrenders himself to evil, so there is a progressive increase in the Penalty which he suffers.