All praise be to Allah! May peace and blessings be upon Allah's Messenger and upon his family and Companions! To proceed;
We have received a question from some Pakistani Muslims that can be summarized as follows:
What is the ruling on whoever who calls for application of socialist and communist principles and fights the rulings of Islam? What is the ruling on a person who helps such people in their demands, scorns those who call for the application of (Shari`ah of) Islam, speaks ill of them and slanders them? Is it permissible to allow those people to be mosque Imams and preachers?
Answer: All praise be to Allah! May peace and blessings be upon Allah's Messenger, his family, Companions and those who followed his guidance! There can be no doubt that Muslim rulers must judge according to Shari`ah (Islamic Law) in all affairs. Moreover, they have to fight any other laws that oppose Shari`ah. This is indisputable and unanimously agreed upon by all Muslim scholars.
But no, by your Lord, they can have no Faith, until they make you (O Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ) judge in all disputes between them, and find in themselves no resistance against your decisions, and accept (them) with full submission.
O you who believe! Obey Allâh and obey the Messenger (Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ), and those of you (Muslims) who are in authority. (And) if you differ in anything amongst yourselves, refer it to Allâh and His Messenger (ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ), if you believe in Allâh and in the Last Day. That is better and more suitable for final determination.
And whosoever does not judge by what Allâh has revealed, such are the Kâfirûn (i.e. disbelievers of a lesser degree as they do not act on Allâh's Laws). And whosoever does not judge by that which Allâh has revealed, such are the Zâlimûn (polytheists and wrongdoers of a lesser degree). And whosoever does not judge by what Allâh has revealed (then) such (people) are the Fâsiqûn [the rebellious i.e. disobedient (of a lesser degree) to Allâh].
Muslim scholars unanimously agreed that whoever claims that the judgment of anyone other than Allah is better than the judgment of Allah or that the guidance of anyone other than the Prophet (may peace be upon him) is better than the guidance of the Prophet is a disbeliever. Similarly, they unanimously agreed that whoever claims that it is permissible for a Muslim to act upon laws other than the Shari`ah revealed to Muhammad (peace be upon him) is a misleading disbeliever.
According to this evidence from the Qur'anic and consensus of Muslim scholars, the questioner and other Muslims can realize the fact that whoever calls for socialism, communism or any other destructive ideology that opposes the laws of Islam is a misleading disbeliever that is even more misleading than the Jews and the Christians, because they are deemed as atheists who have no faith in Allah or the Day of Resurrection.
I hope what we have mentioned above is sufficient to those seeking the truth. Allah says the truth and guides to the right path. We ask Allah (Glorified be He) to settle the Muslim affairs and unite them! May Allah destroy and disunite the enemies of Islam, and protect Muslims from their evil. Allah is Able to do all things! May Allah's peace and blessings be upon His servant and prophet Muhammad and upon his family and Companions!