An article in English in which Imam Ibn Al-Qayyem explains the five dangerous factors that corrupt hearts. They are excessive socializing, wishful thinking, attachment to others besides Allah, eating to one’s fill, and excessive sleep. In this article, he mentions their common effects of all as well as their unique effects.
An article in French preaches and contains important words about the reasons and ways to avoid the torture in graves, quoted from the Book "Ar-Ruh" written by Ibn Alqayyem.
An article translated into German confirms that sins have profound impacts on bodies and hearts and disastrous results in the lives of nations and peoples. It mentions some of these effects excerpted from Imam Ibn Al-Qayyim's book "Malady and Remedy".
Polishing the Hearts: Ibn AlQayyim built up a ruling to polish the hearts based on the Quran versus like when Allah said: (O you who believe! Remember Allaah and remember Him a lot).