Causes:
 
"O, believers, hearts which are filled with malice, which are defiled by doubt are straying from the path into darkness, the hearts which contain vile fancies, such hearts are abode of Satan and of devils."
 

(Pir Pandiyat-i Jawanmardi, p.23)

Remedies:
 
"But pure, loving and clean hearts which contain no malice and enmity at any one, or lust for things of this world, those in which there is nothing except the thought of the Truth, — such hearts are the Throne of the Merciful, and the seat of angels. Therefore, O, believers, see God in your hearts, keeping hearts well-polished, removing rust, dust, doubt and hypocrisy from the mirror of your hearts by the brush of firm faith (yaqin), and wash it with the water of religious knowledge, so that you may see God in that mirror of your hearts. If you love God, turn away your hearts from evil-minded traitors, so that they do not make you similar to themselves. God has turned His face from traitors who do not recognize the Truth, and have lost touch with the Imam of the time."
 

(Pir Pandiyat-i Jawanmardi, p.23)