When Allah commands us to give up sins and to avoid them it is not because our sins will harm Him. It is only us who will benefit by avoiding sins. Likewise, we alone will be affected by the sins we commit. It was the habit of the righteous ancestors to think about their sins whenever they were faced with hardship in anything. In fact, sins have many bad effects on the lives of the sinners. How can sins change our lives? What are the effects of sins on our well-being? Imam Ibn Al-Qayyim Al-Jawziyah explains to us these effects in his well-known book Al-Jawab Al-Kafi:
• Prevention of knowledge: Knowledge is a light which Allah throws into the heart and disobedience extinguishes this light.
Imam Ash-Shafi`i said: “I complained to Wakee` about the weakness of my memory, so he ordered me to abandon disobedience and informed me that knowledge is light. He said that the light of Allah is not given to the disobedient.”
• Prevention of sustenance: Just as righteousness brings about sustenance, the abandonment of righteousness causes poverty. There is nothing which can bring about sustenance like the abandonment of sins.
• Prevention of obedience (to Allah): If there was no other punishment for sin except that it prevents one from obeying Allah then this would be sufficient.
• Disobedience weakens the heart and the body: The fact that it weakens the heart is clear. Disobedience continues to weaken the heart until its life ceases completely.
• Disobedience reduces one’s lifespan and destroys any blessings: Just as righteousness increases one’s lifespan, sinning reduces it.
• Legacy of the cursed: Every type of disobedience is the legacy of a nation from among those which Allah destroyed. Sodomy is a legacy of the people of Lot, taking more than one’s due right and giving what is less is a legacy of the people of Shu`aib, spreading mischief and corruption is a legacy of the people of Pharaoh and pride, including arrogance and tyranny, is a legacy of the people of Hud. So the disobedient one is somehow a part of those nations who were the enemies of Allah.
• Disobedience is a cause of the servant being held in contempt by his Lord: Al-Hasan Al-Basri said: “They became contemptible in (His sight) so they disobeyed Him. If they were honorable (in His sight) He would have protected them.”
• Effect of sins on others: The ill-effects of the sinner fall upon those around him as well as the animals as a result of which they are touched by harm.
• Living in sin: The servant continues to commit sins until they become very easy for him and seem insignificant in his heart and this is a sure sign of destruction. Every time a sin becomes insignificant in the sight of the servant it becomes great in the sight of Allah.
• Disobedience brings humiliation and lowliness: Every aspect of honor lies in the obedience of Allah. Ibn Al-Mubarak said: “I have seen sins kill the hearts. And humiliation is inherited by their continuity. The abandonment of sins gives life to the hearts. And the prevention of your soul is better for it.”
• Disobedience corrupts the intellect: The intellect has light and disobedience extinguishes this light. When the light of the intellect is extinguished it becomes weak and deficient.
• Sealing of the heart: When disobedience increases, the servant’s heart becomes sealed so that he becomes of those who are heedless. The Exalted said: But no! A stain has been left on their hearts on account of what they used to earn (that is, their actions) (Al-Mutaffifin 83: 14).
• Sins cause various types of corruption to occur in the land: Corruption of the water, the air, the plants, the fruit, and the dwelling places. The Exalted said: Mischief has appeared on the land and the sea on account of what the hands of men have earned; that He may give them a taste of some of (the actions) they have done, in order that they may return (Ar-Rum 30: 41).
• Disappearance of modesty: Modesty is the essence of the life of the heart and is the basis of every good. Its disappearance is the disappearance of all that is good. The Prophet (peace and blessings be upon him) said: “Modesty is goodness, all of it.”
• Sins weaken and reduce the magnification of Allah the Almighty in the heart of the servant.
• Sins are the cause of Allah forgetting His servant: Sinning also causes Allah to abandon him and leave him to fend for himself with his soul and his Satan and in this is destruction from which no deliverance can be hoped for.
• Being removed from the realm of benevolence: When a persons sins, benevolence is removed from his heart. When benevolence fills the heart it prevents it from disobedience.
• Disobedience causes the favors (of Allah) to cease and makes His revenge lawful: No blessing ceases to reach a servant except because of a sin, and no retribution is made lawful upon him except because of a sin. Ali ibn Abi Talib (may Allah be pleased with him) said: “No trial has descended except due to a sin and it (the trial) is not repelled except by repentance.”