Imam Ibn ul Qayyim al Jawziyyah

There are ten useless matters:

1 - Knowledge that is not acted on
2 - The deed that has neither sincerity nor is based on following the righteous examples of others
3 - Money that is hoarded, as the owner neither enjoys it during this life nor obtains any reward for it   in the Hereafter
4 - The heart that is empty of love and longing for Allah, and of seeking closeness to Him
5 - A body that does not obey and serve Allah
6 - Loving Allah without following His orders or seeking His pleasure
7 - Time that is not spent in expiating sins or seizing opportunities to do good
8 - A mind that thinks about useless matters
9 - Serving those who do not bring you close to Allah, nor benefit you in your life
10 - Hoping and fearing whoever is under the authority of Allah and in His hand; while he cannot bring any benefit or harm to himself, nor death, nor life; nor can he resurrect himself.