Your youth will definitely leave you, and if you do not remain within the sphere of the licit, it will be lost, and rather than its pleasures, it will bring you calamities and suffering in this world, in the grave, and in the Hereafter. But if, with Islamic training, you spend the bounty of your youth as thanks in uprightness and obedience, it will in effect remain perpetually and will be the cause of gaining eternal youth.