The fact that some members will leave the community of Hazrat Mahdi (as) is a great blessing for them

The hadith of our Prophet (saas) reveal that some members will leave the community of Hazrat Mahdi (as), which will consist of very few people in numerical terms. Although these people will know Hazrat Mahdi (as) very well and witness that he possesses the attributes described in the hadith and will do things that only Hazrat Mahdi (as) is capable of doing, they will still abandon him. But the hadith of our Prophet (saas) also state that the departure of these people is all for the best and something very excellent for Hazrat Mahdi’s (as) community. The emergence of insincere people from among this true society will, by Allah’s leave, increase the mutual devotion of the members of the community, and their departure will strengthen his community still further.

The presence of hypocrites in Muslim societies and all their character traits are described in detail in the verses of the Qur’an. These people are false individuals who act alongside believers, who claim to share the same beliefs as them, but who do not really believe at all. These people, who live among true believers who live for Allah’s approval, are not really genuine believers at all. Their dishonesty gradually emerges and they have to leave the Muslim community. Our Prophet (saas) describes the hypocrites who leave Hazrat Mahdi’s (as) community as follows:
 

The hadith describe the hypocrites who emerge from Hazrat Mahdi’s community as "the vile weevils that infest wheat.” Hazrat Mahdi’s (as) community is compared to "a blessing promised for the future, like wheat, that will be spread out, grow and develop and bring forth abundance.” The hypocrites are the "vile entities such as weevils that try to damage the wheat from the inside.” The hadith describes how the owner of the wheat will clean it, but that it will become infested again, and that he will repeat the process over and over again until no weevils are left in it.  In the same way that the vile and loathsome weevils are all picked out and the wheat made pure, so the community of Hazrat Mahdi will eventually be rid of all hypocrites and made completely pure and able to do its duty as an immaculate community.

Allah provides important information in the Qur’an about how the hypocrites in a Muslim society will reveal themselves. This is described as follows: 

Then He sent down to you, after the distress, security, restful sleep overtaking a group of you, whereas another group became prey to anxious thoughts, thinking other than the truth about Allah – thoughts belonging to the Time of Ignorance* –  saying, ‘Do we have any say in the affair at all?’ Say, ‘The affair belongs entirely to Allah.’ They are concealing things inside themselves which they do not disclose to you, saying, ‘If we had only had a say in the affair, none of us would have been killed here in this place.’ Say, ‘Even if you had been inside your homes, those people for whom killing was decreed would have gone out to their place of death.’ So that Allah might test what is in your breasts and purge what is in your hearts. Allah knows the contents of your hearts. (Surat Al ‘Imran, 154)

As described in the verse, at times of difficulty when hypocrites confront situations that test their earthly desires and when they should make sacrifices for Muslims, they immediately expose themselves through their apathy and lack of interest. The slightest threat of harm to their own self-interest immediately leads them to rebel against the faith and speak words of denial (surely Allah is beyond that.) The fact is, however, that these things are all tests designed to expose such dishonest individuals.

The main reasons for this rebellion on the part of hypocrites are their love of the life of this world, doubts about the hereafter and sickness in their hearts. The Qur’an reveals how hypocrites within a Muslim society will seek to spread corruption through their desire for the life of this world:
 

Allah fulfilled His promise to you when you were slaughtering them by His permission. But then you faltered, disputing the command, and disobeyed after He showed you what you love.* Among you are those who want the dunya and among you are those who want the akhira. Then He turned you from them in order to test you – but He has pardoned you. Allah shows favor to the muminun. (Surat Al ‘Imran, 152)

In the same way that people with such a character have always existed in communities of true believers, they will also be present in that of Hazrat Mahdi (as). According to the hadith, those who abandon Hazrat Mahdi’s (as) community will later continue down the path of those who deny him, despite having spent years working alongside the community. These people, who do not share the same belief and honesty as Muslims, and who are disloyal to Allah and the Qur’an and whose fear of Him is weak, may abandon Hazrat Mahdi (as) when events conflict with their own self-interest. But the hadith of the Prophet (saas) state that this will do no harm to Hazrat Mahdi (as) and the people with him, and will actually, work in their best interests. By Allah’s leave, Hazrat Mahdi (as) and his followers will continue to enjoy success in their auspicious work. This is described in another hadith: