Declare your jihad on thirteen enemies you cannot see - Egoism, Arrogance, Conceit, Selfishness, Greed, Lust, Intolerance, Anger, Lying, Cheating, Gossiping and Slandering. If you can master and destroy them, then will be ready to fight the enemy you can see.
Al-GhazaliDo not dispute with anyone in any matter as far as possible. For in argumentation lies much harm and its evil is greater than its benefit.
Al-GhazaliNeglect not your time, nor use it haphazardly; on the contrary you should bring yourself to account. Structure your litanies and other practices during each day and night. This is how to bring about the spiritual blessing (baraka) in each period. If each of your breaths is a priceless jewel, Be not like the deceived fools who are joyous because each day their wealth increases while their life grows ever shorter.
Al-Ghazali