Causing fitnah in this world costs hypocrites an eternity in punishment. This is a torment that will begin when still in this world, and extend into Hell beyond death.
Specifically, they will suffer spiritual torment in this world. They live in perpetual anxiety and fear. Nevertheless, they actually know what they do is merely hypocrisy. For this reason, they feel constant pangs of conscience, throughout their lives.
In addition, they are always fearful, either before or after they have caused fitnah. They fear being discovered by the believers before their hypocrisy is made known. Once they separate from the believers, they live in constant fear of Allah's torment as reward for their evil. The increase in the number of those living by the principles of the Qur'an frightens the hypocrites, for, the more people submit themselves to Allah, the more they regret leaving the believers to pursue their trivial interests. For this reason, when Islamic morality is widely embraced, hypocrites may try to gain the confidence of the believers, claiming a share in their success, saying, "Were we not with you?" Allah relates in the Qur'an that these same things also occurred in the time of our Prophet (saas). The mindset of the hypocrites is conveyed in the Qur'an as follows:
Give news to the hypocrites that they will have a painful punishment. Do those who take the disbelievers as protectors, rather than the believers, hope to find power and strength with them? Power and strength belong entirely to Allah. (Surat an-Nisa', 138-139)
Those who anticipate the worst for you say, "Were we not with you?" Whenever you gain a victory from Allah, but if the disbelievers have a success they say, "Did we not have the upper hand over you and yet in spite of that keep the believers away from you?" Allah will judge between you on the Day of Rising. Allah will not give the disbelievers any way against the believers. (Surat an-Nisa', 141)
The hypocrites, who lived at the time of our Prophet (saas), also tried deceptively to gain the confidence of the believers, in order to share in the spoils gained from victories. The related verse reads:
When you go out to get the booty, those who remained behind will say, "Allow us to follow you," desiring to alter Allah's words. Say: "You may not follow us. That is what Allah said before." They will say, "It is only because you envy us." No indeed! How little they have understood! (Surat al-Fath, 15)
Evidently, hypocrites tried to approach the believers when they witnessed their success, but the believers were not deceived by them. On the contrary, believers announced their hypocrisy to everyone when they attained supremacy, and the hypocrites faced a humiliation in this world before the next.