The most feared disease, which only can be, is the hypocrisy - nifak. We can find many verses in the Holy Quran about this negative. Almighty Allah describes the hypocrites, gives them a description. For example, in Surah al-Anfal (the Trophies) speaks about their belief. They consider those who believe in Allah naive people to believe in fiction, believing that religion - is a fraud, "This is the hypocrites and those in whose hearts was a disease, said: "Their religion has deluded those [Muslims]." (The Holy Quran, 8:49). And also: "And [remember] when the hypocrites and those in whose hearts is disease said, " Allah and His Messenger did not promise us except delusion." (The Holy Quran, 33:12).
In Surah "At-Tauba" (Repentance), highlights their anxiety that is about to unfold their criminal intent and will be made public: "The hypocrites fear that they will be sent down sura, which tells them about what is in their hearts. Say, "Mock [as you wish]; indeed, Allah will expose that which you fear." (The Holy Quran, 9:64). Almighty Allah ensures that will come such moment when all concealed available to the public. Further in the same Surah Allah points to such properties hypocrites, as the desire for the forbidden, stinginess, negligence in the remembrance of Allah, and then warns of imminent severe punishment: "The hypocrite men and hypocrite women are of one another. They enjoin what is wrong and forbid what is right and close their hands. They have forgotten Allah , so He has forgotten them [accordingly]. Indeed, the hypocrites - it is they who are the defiantly disobedient. Allah has promised the hypocrite men and hypocrite women and the disbelievers the fire of Hell, wherein they will abide eternally. It is sufficient for them. And Allah has cursed them, and for them is an enduring punishment." (The Holy Quran, 9:67,68).
The hypocrites were always among the people and always will be. We learn from the following verses of Surah "Tauba": And among those around you of the bedouins are hypocrites, and [also] from the people of Madinah. They have become accustomed to hypocrisy. You, [O Muhammad], do not know them, [but] We know them. We will punish them twice [in this world]; then they will be returned to a great punishment. (The Holy Quran, 9:101).
In this world of hypocrites were among the believers, but the Day of Judgment they will be separated from each other. They will try again to be among the faithful, but believers waiting for the abode of mercy - Paradise, and the hypocrites and disbelievers is the punishment of hell: "On the [same] Day the hypocrite men and hypocrite women will say to those who believed, "Wait for us that we may acquire some of your light." It will be said, "Go back behind you and seek light." And a wall will be placed between them with a door, its interior containing mercy, but on the outside of it is torment." (The Holy Quran, 57:13).
In the Qur'an, there is a whole sura, which is called - "Al-Munafikun" (Hypocrites)
"When the hypocrites come to you, [O Muhammad], they say, "We testify that you are the Messenger of Allah ." And Allah knows that you are His Messenger, and Allah testifies that the hypocrites are liars. They have taken their oaths as a cover, so they averted [people] from the way of Allah . Indeed, it was evil that they were doing. That is because they believed, and then they disbelieved; so their hearts were sealed over, and they do not understand. And when you see them, their forms please you, and if they speak, you listen to their speech. [They are] as if they were pieces of wood propped up - they think that every shout is against them. They are the enemy, so beware of them. May Allah destroy them; how are they deluded? And when it is said to them, "Come, the Messenger of Allah will ask forgiveness for you," they turn their heads aside and you see them evading while they are arrogant. It is all the same for them whether you ask forgiveness for them or do not ask forgiveness for them; never will Allah forgive them. Indeed, Allah does not guide the defiantly disobedient people. They are the ones who say, "Do not spend on those who are with the Messenger of Allah until they disband." And to Allah belongs the depositories of the heavens and the earth, but the hypocrites do not understand." (The Holy Quran, 63:1-7).
The Messenger of Allah (ﷺ) pointed us to the following three quality hypocrites hadith narrated by Abu Hurayrah:
عَنْ أَبِي هُرَيْرَةَ ، عَنِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ، قَالَ : " آيَةُ الْمُنَافِقِ ثَلَاثٌ ، إِذَا حَدَّثَ كَذَبَ ، وَإِذَا وَعَدَ أَخْلَفَ ، وَإِذَا اؤْتُمِنَ خَانَ "
"The hypocrites have three features: they say, is lying and when promised, break promises, and when the offer guarantees of anything, betray" (Sahih al-Bukhari, 33).
Islamic scholars say that if these three qualities are united in one person, he is a pure hypocrite. And if there is one quality that this man is an urgent need to repent and try to improve. As we have seen, in the Qur'an, Allah calls the hypocrisy of the disease. So, we can not allow this disease has become chronic.
Scientists have identified two groups of hypocrites:
Hypocrites in itikade (faith)
Hypocrites in the acts
About the first group of hypocrites, the Quran says:
إِنَّ الْمُنَافِقِينَ فِي الدَّرْكِ الْأَسْفَلِ مِنَ النَّارِ وَلَن تَجِدَ لَهُمْ نَصِيرًا ﴿١٤٥﴾
"Indeed, the hypocrites will be in the lowest depths of the Fire - and never will you find for them a helper." (The Holy Quran, 4:145).
But the second group - a group of risk. The man himself unwittingly may move from the second category of hypocrites, hypocrites acts in the first - in aqidah hypocrites, ie unbelievers, and even worse than unbelievers.
How not to be a hypocrite, should we look out for this? From the history of Islam is known that all the righteous fear of them until their death.
Mu'min believer until the end of his life must be wary of falling into kufr. It is sufficient that one of the Hadith Qudsi Allah says: "I do not combine the two fears and two security." That is, if a person is afraid of Allah in this world, then in the Hereafter he will be safe. If on the contrary, was not afraid of God, the Day of Judgment he will experience this terrible fear.