In the first place, we would like to make it clear that Almighty Allah gives to all those who fear Him a criterion that helps them see what is right and what is wrong. This is the natural outcome of piety and Allah-fearing. Almighty Allah says: “O ye who believe! If ye keep your duty to Allah, He will give you discrimination (between right and wrong) and will rid you of your evil thoughts and deeds, and will forgive you. Allah is of infinite bounty.” (Al-Anfal: 29)
Sheikh `Atiyyah Saqr, former head of Al-Azhar Fatwa Committee, states: “It is reported in Al-Qurtubi’s exegesis of the Qur’an that Abu `Issa At-Tirmidhi reported on the authority of Abu Sa`id Al-Khudri that the Prophet (peace and blessings be upon him) said: “Beware of a believer’s insight, for he is guided by a divine light.” Then he recited: “Lo! therein verily are portents for those who read the signs.” (Al-Hijr: 75) (It is said to be a gharib hadith, i.e., there was only one original narrator)
At-Tirmidhi Al-Hakeem reported on the authority of Anas that Allah’s Messenger (peace and blessings be upon him) said: “Really, among Allah’s servants there are people who can assess others at sight.”
The Sufis claim that this is karamah (a divinely-bestowed extraordinary ability), while others said that it is a kind of deduction based on signs. There are explicit signs that are manifest for all from the first sight, and implicit signs that cannot be realized by ordinary people. For example, Ibn `Abbas said: “Whenever someone asks me, I realize whether he is a jurist or not.”
Sheikh Farahaat As-Said Al-Munji, a prominent Al-Azhar scholar, adds:
“A believer has an extraordinarily analytical eye; he can penetrate people’s inner self and realize what is going on inside them. This ability is granted by Allah Almighty to believers; nobody teaches them such extraordinary knowledge.
No one has this divine ability except true believers who regularly observe acts of worship, obey Allah in all their affairs, shun major sins altogether, avoid slight mistakes as much as they can and seek halal (lawful) earnings and provision, for Allah Almighty is Good and so He accepts nothing but good deeds. Therefore, a true believer must abandon wrongdoing altogether, even if it does not incur any worldly punishment. Such deeds are like gossip, calumny, lying, envy, hatred and other prohibited actions.
It is reported that once the Prophet (peace and blessings be upon him) was sitting with his Companions. Then he said to them: “A man of the people of Paradise will come now.” Then a man came. The same incident repeated for three consequent days: the same man came after the Prophet said so on the three days. `Abdullah ibn `Umar (may Allah be pleased with both father and son) was eager to know what were the deeds that qualified that man to be one of the people of Paradise. So he went to the house of that man, who hosted Ibn `Umar for three days. During those days Ibn `Umar watched the man and found that he did no extra worship; he used to observe the five Prayers at their due time and perform the optional Prayers and sleep. `Abdullah ibn `Umar asked the man why the Prophet (peace and blessings be upon him) had described him as one of the people of Paradise though he observed no extra worship than others do, as he noticed during the previous three days. The man answered that he never spent a night while harboring any feeling of envy or hatred towards anybody. That was what qualified him to be among the dwellers of Paradise.
Therefore, keeping steadfast in observing acts of worship and abandoning all excessive deeds and sensations are the characteristic of a true believer. They qualify a believer to have true insight that directs him with divine guidance. True insight gives one the ability to expect things before they happen.
Then a Muslim must be sincere in worship. Sincerity enhances steadfastness in worship, as it keeps one away from hypocrisy and showing off. Allah Almighty says: “Say (O Muhammad): Lo! I am commanded to worship Allah, making religion pure for Him (only).” (Az-Zumar: 11)
A believer is one who regularly observes acts of worship with complete sincerity and dedication and as perfectly as possible. He must keep away from consuming haram (unlawful) provision and abandon all prohibited obvious and hidden sins. A true believer is pious and conscious of Allah in all his deeds. Hence he has divinely-bestowed extraordinary insight.”
Almighty Allah knows best.