navedz.com a muslim's Quest for the truth
Ibn Qayyim al Jawziyyah (may Allah have mercy on him) said, describing the effects of sin:
“Sin corrupts reason, for reason is light, and sin inevitably extinguishes the light of reason. If its light is extinguished it becomes weak and imperfect. One of the salaf said: No one disobeys Allah but his reason is lost.
This is obvious, because if his reason was present, it would have prevented him from committing sin when he is under the full control of Allah, may He be exalted, or how could he commit sin openly when He is watching him, and he is enjoying His blessings and His angels are bearing witness over him and watching him, and the teachings of the Quran forbid that and the implication of faith and the remembrance of death and the Fire should restrain him.
The good of this world and the Hereafter that he misses out on because of sin is many times greater than the pleasure he may get from it. Can anyone who takes lightly all that we have mentioned above still have sound reason?
…If sins accumulate, then a seal is placed on the sinner’s heart and he becomes one of the heedless, as one of the salaf said concerning the words of Allah (interpretation of the meaning): “Nay! But on their hearts is the Raan (covering of sins and evil deeds) which they used to earn” [Surah al-Mutaffifeen 83:14] – he said: This is sin after sin.
Al-Hasan said: It is sin upon sin, until the heart becomes blind. And someone else said: When their sins and acts of disobedience become many, they encircle their hearts.
The basic principle concerning that is that the heart is corroded (lit. rusts) by sin, so if sin increases, the corrosion prevails until it becomes raan, then it prevails until it becomes a seal, and the heart becomes covered and enveloped. If that happens after he has been guided and had insight, then he will be reversed and turned upside down. At that point his enemy takes over and leads him wherever he wants.
thought provoking !