Q 1: Many Muslims are lenient regarding ruling by other than Allah's Law and think that this leniency does not affect their adherence to Islam. Some even deem judging by laws other than those revealed by Allah as lawful and are indifferent to the consequences of this. What is the ruling on this?
A: This requires a detailed answer. Anyone who rules by laws other than those laid down by Allah while knowing the obligation of ruling according to the Law revealed by Allah, and is aware that by doing so they have violated the Shari'ah (Islamic law), but in spite of this they regard this matter as permissible and believe that they have done nothing wrong and that it is permissible to rule by other than Allah's Law is a Kafir (disbeliever) who is guilty of major Kufr (disbelief) according to all Muslim scholars. Ruling according to other than Shari'ah includes judgment according to manmade laws which are laid down by Christians, Jews and the like who claim that it is permissible to use these laws in judgment, or claim that they are better than or as good as Allah's Laws, and that people have the choice either to rule according to the Qur'an and Sunnah or manmade laws. Indeed, anyone who believes in the validity of these aforementioned claims has committed Kufr by the Ijma' (consensus) of Muslim scholars as mentioned previously. As for those who rule by other than Allah's revealed Law to satisfy an inclination or to secure a transient worldly gain, while admitting that by doing so they are disobeying Allah and His Messenger (peace be upon him) and have committed a grave Munkar (an act unacceptable or disapproved of by Islamic law and Muslims of sound intellect) and that it is obligatory on them to rule according to Allah's Law, they will not be guilty of major Kufr. Nevertheless, they are guilty of a grave Munkar, a major sin and a minor act of Kufr (disbelief); this is the opinion of Ibn 'Abbas, Mujahid and other scholars. By doing so they are judged to have committed an act of Kufr, Zhulm (injustice), and Fisq (flagrant violation of Islamic law) that does take them out of Islam, as it does not constitute major Kufr.
This is the opinion of AhlulSunnah walJama'ah (those adhering to the Sunnah and the Muslim main body). Allah (Exalted be He) says, And so judge (you O Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ) among them by what Allâh has revealed 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]. 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. Do they then seek the judgement of (the days of) Ignorance? And who is better in judgement than Allâh for a people who have firm Faith. The Judgment of Allah is certainly the best judgment and must be followed for it achieves the welfare and happiness of this Ummah (Muslim nation), in this world and in the hereafter, and the wellbeing of the entire world, but regretfully most people are unaware of this fact. Allah is the One sought for help. There is neither might nor power except with Allah, The Most High, the Most Great.