Until the Day of Judgment, Satan has sworn to lead mankind astray, in an effort to make them members of his party. As Allah declares when he said, "Satan has gained mastery over them, so he has made them forget the remembrance of Allah; they are the Satan's party; now surely the Satan's party are the losers" (Surat al-Mujadala: 19), Satan has succeeded in his desires with those who deny the existence of Allah. He has surrounded them from all sides, made them forget the remembrance of Allah, and acquired absolute mastery over them. Thus, these people became the party of Satan, as creatures calling others to denial, sin and evil, as does the devil.
However, the condition of those who sincerely believe in Allah is certainly different. Satan may directly influence those who deny Allah. However, as true believers firmly put their faith in Allah, Satan fails in influencing them. For instance, he could in no way prevent them from striving for Allah's sake. He cannot prevent them from fulfilling their religious duties, performing their prayers, doing good and being morally upright, reciting the name of Allah, and from sacrifing themselves to fight both with their belongings and their lives.
Well aware of this fact, the devil is compelled to search for even more devious methods to influence true believers. As he is not capable of directly hindering the good deeds done in Allah's sake, he tries to mix evil into the good intentions of true believers performing these deeds; to make them turn towards objectives other than Allah's consent, and to prevent them from turning towards Allah devoutly, by thus impinging their sincerity. In the Qur'an, Satan's determination to this end is emphasized by his very own words. The verses relating these words are as follows:
I will lead them astray and fill them with false hopes. I will command them and they will cut off cattle's ears. I will command them and they will change Allah's creation. Anyone who takes Satan as his protector in place of Allah has clearly lost everything. He makes promises to them and fills them with false hopes. But what Satan promises them is nothing but delusion. (Surat an-Nisa': 119-120)
He said, "By Your misguidance of me, I will lie in ambush for them on your straight path. Then I will come at them, from in front of them and behind them, from their right and from their left. You will not find most of them thankful." (Surat al-A'raf: 16-17)
As indicated in these verses, Satan attempts to master true believers by "leading them astray and filling them with false hopes," by "laying in ambush for them on Allah's straight path," and by "coming at them, from in front of them and behind them, from their right and from their left."
He uses efforts to make them see right as wrong, good as evil, fine as ugly, and evil as good. He strives to hinder them from doing a good deed in Allah's sake by planting doubt and exciting vain desires in their hearts. He endeavors to lure true believers to pursue even that which contradicts the morality of the Qur'an by adorning it to make it attractive.
If necessary, to accomplish the above-mentioned objectives, Satan depends for help on those who befriend him and deny Allah. He uses their mouths to speak his suggestions, and their words to express his plans. It is through such crafty tactics that he approaches true believers.
Certainly, Satan does not openly invite true believers to denial by merely uttering "Do not conform to the Qur'an, do not behave in compliance with Allah's consent or conform to me instead." On the contrary, he tries to deceive them with fraud, ruses and lies. He attempts to prevent them from being sincere and plants various vain desires in their hearts, and tries to make them seek the admiration of others instead of gaining Allah's consent.
For instance, he tries to add the desire to gain people's assent to the intentions of a believer who strives to do a good deed for the sake of Allah. He encourages him to praise his own virtues, and inflate his ego.
Yet, to take pride in one's self while performing a good deed will prevent him from attaining sincerity. If he truly chooses to perform a deed that is self-sacrificing, he should be doing it to gain Allah's consent. Therefore, there should be no need to make his deeds public. In any case, Allah sees and hears him. However, Satan presents this desire in a more seemingly innocent light, through such reasoning as "They will trust and love you more if they know how morally upright you are and how you conform to the Qur'an. Anyway, it is a perfectly legitimate desire." It is of course a legitimate desire, however, one would be behaving more in line with the Qur'an if he seeks this recognition from Allah and leaves the matter of his public perception in His hands. If he behaves differently, he will risk being overcome by the wrongdoings that are rejected by the Qur'an. Such behavior would amount to worshipping to be seen, to become important, and in taking pride in one's self. All such behavior is opposed to one's sincerity and purity, qualities that are only acquired while performing worship to merely gain Allah's consent.
Satan's plan to harm the sincerity of true believers, which will last until the Day of Judgment, dates back to the time of Adam (as). He approached Adam (as) with the same sly and deceitful strategies, and tried to make him perceive good as ugly and ugly as good. As announced in the Qur'an, Satan succeeded in persuading Adam (as) and his mate to not heed Allah's prohibition. Thus, he caused them to be driven out of Paradise. This event is explained in the verses of the Qur'an as follows:
We said, "Adam, live in the Garden, you and your wife, and eat freely from it wherever you will. But do not approach this tree and so become wrongdoers." (Surat al-Baqara: 35)
But Satan whispered to him, saying, "Adam, shall I show you the way to the Tree of Everlasting Life and to a kingdom which will never fade away?" (Surah Ta Ha: 120)
Then Satan whispered to them, disclosing to them their private parts that had been concealed from them. He said, "Your Lord has only forbidden you this tree lest you become angels or among those who live for ever." He swore to them, "I am one of those who give you good advice." So he enticed them to do it by means of trickery. Then when they tasted the tree, their private parts were disclosed to them and they started stitching together the leaves of the Garden in order to cover themselves. Their Lord called out to them, "Did I not forbid you this tree and say to you, "Satan is an outright enemy to you"?" (Surat al-A'raf: 20-22)
Satan did not openly tell Adam and his mate to defy Allah's orders. It is apparent that no true believer would comply with such a suggestion. Thus, he devised other persuasive arguments, and told them that they would become angels and live eternally if they ate the fruit of the forbidden tree. In order to make his lies still more persuasive, he dared even to swear by Allah. The Qur'an warns the true believers against this kind of cunning conceived by the devil:
Children of Adam! Do not let Satan tempt you into trouble as He expelled your parents from the Garden, stripping them of their covering and disclosing to them their private parts. He and his tribe see you from where you do not see them. We have made the satans friends of those who do not believe. (Surat al-A'raf: 27)
Those who are guided by the Qur'an are prepared in advance against unfounded concerns, vain desires and deceitful ruses of the devil. As declared in the verse, "Those who believe fight in the Way of Allah. Those who disbelieve fight in the way of false gods. So fight the friends of Satan! Satan's scheming is always feeble." (Surat an-Nisa': 76) , the strategy of the devil is weak and is comprised merely of hollow deceptions. True believers comprehend that this whispering voice is that of Satan and immediately seek refuge in Allah as related in the following verse,
If an evil impulse from Satan provokes you, seek refuge in Allah. He is All-Hearing, All-Seeing. As for those who do their duty, when they are bothered by visitors from Satan, they remember and immediately see clearly. (Surat al-A'raf: 200-201)
As soon as they find refuge in Allah, they become capable of interpreting the events in the light of the Qur'an. They acquire an understanding aiding them to distinguish right from the wrong. Therefore, the false imputations of the devil fail due to the powerful faith of true believers.
Likewise, as the Qur'an underlines in the following verse, Satan exercises no authority over true believers who put their trust and faith in Allah, and who take Allah as their only Guardian:
But as for My servants, you will not have any authority over them. Your Lord suffices as a guardian. (Surat al-Isra': 65)
As mentioned in the Qur'an, Satan is influential over those guarded by him, and those who associate others as divinities beside Allah:
He has no authority over those who believe and put their trust in their Lord. He only has authority over those who take him as a friend and associate others with Allah. (Surat an-Nahl: 99-100)
It is stated that the devil could not affect the sincere and pure servants of Allah:
He said, "My Lord, because You misled me, I will make things on the earth seem good to them and I will mislead them all, every one of them, except Your servants among them who are sincere." (Surat al-Hijr: 39-40)
For this reason, the sincere and righteous believers have no reason to fear the cunnings and deceitful traps set by the devil, as they know for certain that the devil holds no power over them. They only fear Allah. Those who fear Satan are the ones who befriend him, and those who have entered his fold. This reality is unfolded in the Qur'an as follows:
It was only Satan frightening you through his friends. But do not fear them—fear Me if you believe. (Surah Al 'Imran: 175)
In the Qur'an, Allah announces that Satan will expend all efforts to plant vain desires and deviance in the hearts of all people, including the prophets. This is a special kind of trial created to distinguish between those who have a disease in their heart and those who are sincere believers. Those who have attained purity and those who have knowledge are in no way influenced by these vain desires of Satan. They are well aware that the devil holds no independent power, and is indeed created and fully controlled by Allah. The devil is powerless to lead believers astray, to hinder their sincerity or guide them to the wrong path, without the Will of Allah. When Satan tries to "place vain desires in their hearts," the Muslims' belief that the Qur'an is undoubtedly a true blessing from Allah is strengthened. This truth is revealed in a verse as follows:
We did not send any Messenger or any Prophet before you without Satan insinuating something into his recitation while he was reciting. But Allah revokes whatever Satan insinuates and then Allah confirms His Signs—Allah is All-Knowing, All-Wise—so that He can make what Satan insinuates a trial for those with sickness in their hearts and for those whose hearts are hard—the wrongdoers are entrenched in hostility—and so that those who have been given knowledge will know it is the truth from their Lord and believe in it and their hearts will be humbled to Him. Allah guides those who believe to a straight path. (Surat al-Hajj: 52-54)