Written by Ibn Qayyim al-Jawzee, Madaarij as-Saalikeen, vol. 1, pp. 443-9
The Five Heart Corrupters are : Excessive socializing, wishful thinking, attachment to others besides Allaah, eating to one’s fill, and sleep. These five factors are the greatest corrupters of the heart. In this article I will mention the effects that are common to all of them as well as those effects that are unique to each of them.
Know that the heart is on a journey to Allaah, Most Great and Glorious, and to the world of the Hereafter, and [that it is able to] discover the path of truth as well as the faults of the soul and of deeds. Its path is traversed with its light, life, strength, health, determination (‘azm), the soundness of its hearingand sight, as well as the absence of distractions and impediments from it. These five (corrupters) extinguish its light, distort its vision, muffle its hearing, if they do not deafen it, dumfound it, and weaken its powers/strengths altogether. They weaken its health, slacken its drive, halt its decisions, and reverse it (sending it backwards). And if one does not sense it, his heart is dead – as wounding a corpse does not inflict pain. They are impediments that prevent it from achieving its perfection, and prevent it from arriving to what it was created for, and making its pleasure and happiness ibtihaah and its enjoyment in arriving to it.
For there is no pleasure, sweetness, ibtihaaj, or perfection except by knowing Allaah and loving Him, peace in remembrance of Him, happiness and ibtihaaj in being close to Him and desiring to meet Him. This is (the heart’s) early paradise. As there will be no pleasure or success for it in the Hereafter, except by being its neighbour in the abode of pleasure in the early paradise. It has two paradises. It will not enter the second of the two if it did not enter the first.
I heard Shaykhul-Islaam Ibn Taymiyyah – may Allaah have mercy on him – say: “Indeed there is a paradise in this world, whoever doesn’t enter it will not enter the paradise of the Hereafter.”
… Some of those known for their love of Allaah (al-muhibboon) [were reported to have] said: “The truly unfortunate people of this world are those who leave the world without tasting the sweetest thing it contains.” When they were asked what it was, they replied: “The love of Allaah, to feel comfortable in His company, to desire to meet Him, turning towards Him and turning away from everything besides Him.” Or some words similar to that. Everyone who has a heart bears witness to this and knows it as a result of having tasted it. And these five matters cut [the person] off from this, block the heart from it, impede its journey, cause sicknesses and defects for which, if the sick person does not realize it, [destruction] is feared.