Qur'an, Al-Isra, Surah 17:18-19
'Those who are concerned only with this fleeting life, will soon suffer in the manner we choose. We determine people's fate as we please. We have prepared hell for those in love with this fleeting life; they will burn within its flames, despised and helpless.' But the true believers who are concerned with the life to come, and strive for it with all their souls, will have their efforts rewarded by God.