We shall therefore discuss these four evils, where they occur, how they affect a person, how to guard against them before they occur, and how to repel them once they have occurred.
Before discussing this, however, we must explain what evil is and what its true nature is.
We say: Evil refers to two things: pain and whatever leads to it. It denotes nothing beyond these. Evils, then, are pains and their causes. Sins, disbelief, associating partners with Allah, and all forms of wrongdoing are evils, even if those who commit them find some purpose or pleasure in them. They are evils because they cause pain and lead to it, just as other causes lead to their effects. Pain follows from them just as death follows from taking lethal poisons, having one’s throat cut, being burned in fire, being strangled with a rope, and other causes that inevitably produce their effects—unless something prevents the cause from taking effect, or it is counteracted by something stronger that more powerfully brings about the opposite result. Thus, the causal effects of sins may be counteracted by strength of faith and by the greatness and abundance of good deeds that erase sins. These may outweigh the causes of punishment in quantity or quality, so that the stronger repels the weaker.
Such is the case with all opposing causes, such as the causes of health and illness, or weakness and strength.
The point is that these causes, which contain some pleasure, are evil even if the soul gains immediate delight through them. They are like delicious, appetizing food that is poisoned: the person eating it enjoys its taste and finds it easy to swallow, but before long it takes its toll on him. So it inevitably is with sins and acts of disobedience. Even if the Lawgiver had not informed us of this, actual events, experience, and both the elite and the common people would be among its strongest witnesses.
Has anyone ever lost a blessing except through the ill effects of his own disobedience? When Allah bestows a blessing upon a servant, He preserves it for him and does not take it away until the servant himself strives to bring about its loss:
13:11 “Indeed, Allah does not change the condition of a people until they change what is in themselves. And when Allah intends harm for a people, none can avert it, nor do they have any protector besides Him.”