O you, who spends his lifetime disobeying his Lord, no one amongst your enemies is wicked to you more than you are to yourself
Ibn Qayyim Al-JawziyyaRepel the thought, for if you don't, it becomes an idea. So repel the idea, for if you don't it will become a desire. So fight against that(desire), for if you don't, it will become a determination and a passion. And if you don't repel that, it will become an action. And if you don't replace it with its opposite, it will become a constant habit. So at that point, it will be difficult for you to change it.
Ibn Qayyim Al-JawziyyaDoom comes about because of neglecting to evaluate one's self and because of just following one's whims.
Ibn Qayyim Al-JawziyyaAnd verily for everything that a slave loses there is a substitute, but the one who loses Allah will never find anything to replace Him.
Ibn Qayyim Al-Jawziyya