All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
First of all, it should be noted that the definite truth about which there is no doubt is that it is only Allaah who knows the Unseen; Allaah says (what means): {Say, “None in the heavens and earth knows the unseen except Allaah, and they do not perceive when they will be resurrected.”}[Quran 27:65] This is a true and firm text that cannot be reversed under any circumstances.
Secondly, the statement of any person, no matter who he is, should not be given precedence over the words of Allaah and the words of His Messenger ; Allaah says (what means): {O you who have believed, do not put [yourselves] before Allaah and His Messenger but fear Allaah. Indeed, Allaah is Hearing and Knowing.}[Quran 49:1] Ibn Al-Qayyim said about the interpretation of this verse: “It means do not say until he says and do not do until he commands.”
Thirdly, Allaah Almighty may reveal something from the Unseen as He wills to whichever of His servants He wills; for instance, the Prophets knew many matters of the Unseen by way of revelation. This also happened and may still happen to some righteous slaves of Allaah by divine inspirations, as this is something that is confirmed and which cannot be denied. In this regard, please refer to Fatwa 5416.
The evidence that such an inspiration exists is a Hadeeth in which the Prophet, sallallaahu 'alyhi wa sallam, said "There had been among the people before you inspired persons; and if there were any such among this Ummah (the Muslim nation), ‘Umar ibn Al-Khattaab would be one of them." [Al-Bukhari and Muslim] The inspired persons are those to whom Allaah inspired knowledge of some matters of the Unseen.
The same thing applies to true dreams or visions; a person may see a dream about a future event and then the event happens exactly as the person saw in his dream. This is well-known and oft-occurring. The Prophet said that the true dream of a believer is one part of forty-six parts of the prophesy. [Al-Bukhari and Muslim]
Fourthly, the Sufis do not differentiate between divine inspirations and satanic whispers. The divine inspirations happen only to someone who is righteous and pious both outwardly and inwardly in belief, word and deed when it comes to the religion of Allaah. As regards the whispers of the devil, this happens to those who take the devil as their ally, like the deviant sects, innovators and misguided people, as they attribute such miracles to people who are not known to be steadfast in the truth, neither in word nor in deed.
Fifthly, the Sufis base misconceptions on such matters and they glorify those whom they claim are inspired so that simple people love them - which is indeed the approach of innovators and deviated people as stated by the scholars - and hence, they are considered in their eyes as sacred and glorified, and in this manner, they unlawfully consume people’s money. Indeed, the saying of Allaah applies to them (which means): {O you who have believed, indeed many of the scholars and the monks devour the wealth of people unjustly and avert [them] from the way of Allaah. And those who hoard gold and silver and spend it not in the way of Allaah — give them tidings of a painful punishment.}[Quran 9:34]
The matter gets even worse as the hearts of the people become attached to that person after he dies, and they supplicate him and seek his help. This is indeed explicit Shirk about which there is no doubt.
Sixthly, there is an important matter that should not be forgotten, which is that the Sufis do not rely on evidence to support their beliefs and practices but rather believe in anything and follow any methodology, and when they are asked about evidence, they bring any unfounded matters that are not based on sound evidence. For this reason, the Sufis are among the people who falsely attribute Ahaadeeth to the Prophet .
May Allaah allow us all to do what He loves and pleases Him, and may He bring the Muslims back to the true Islam.
Allaah Knows best.