A Message To Every Youth

In his book al-Fawaid, Ibn al-Qayyim mentioned ten useless matters that cannot be benefited from.

However, the greatest of these matters is the wasting of the heart, and the wasting of time. Wasting the heart is done by preferring this worldly life over the Hereafter, and wasting time is done by having incessant hopes. All evil is in following ones desires and having incessant hopes, while all goodness is found in following the right path and preparing oneself to meet Allāh, and Allāh is the source of Assistance.

Here, he summarized all evil in these two issues: wasting of the heart, and wasting of time. Wasting the heart is done by preferring this worldly life over the Hereafter, and wasting time is done by having incessant hopes, and incessant hopes and the following of ones desires are the ultimate manifestation of evil.