As for Allah's Saying (Glorified be He): and find in themselves no resistance against your decisions, and accept (them) with full submission. it means that their hearts should be opened to his judgment and they should have no resistance to it, because it is the undisputable truth. At the same time it is the judgment of Allah (Glorified and Exalted be He). We should submit and feel comfortable toward it without having any objection, not only this but we should have full submission to and confidence in Allah's Ruling as well. This is the duty of all Muslims with respect to any claims or disputes that arise among them, whether relating to religious, financial, or marital affairs.
This is the origin of having Iman in Allah (Exalted be He) and His Messenger (peace be upon him) regarding the application, acceptance, and believing Shari'ah as the arbitrator between people. It is essential, so whoever claims that it is permissible to rule in accordance with other than it or that it is permissible for people to resort to parents, grandparents or positive laws of the east or the west
has no Iman and accordingly will be a disbeliever. Whoever says that Allah's Shari`ah may not be applied but it is better to apply it, laws are better, or that laws are equal to Allah's Shari`ah will be apostatizing from Islam. This apostasy includes three forms:
First: To say that the Shari`ah is better but there is no prohibition to rule by other than it.
Second: To say that the Shari`ah and laws are similar and that there is no difference between them.
Third: To say that laws are better and more worthy of application than Shari`ah, and this is the worst view of all. However, all these views fall under Kufr and apostasy from Islam.
However, if someone views that it is an obligation to rule by the Shari`ah and that it is impermissible to rule by positive laws that contradict it, but they still rule with them for a personal gain, bribe, political affairs, and so on, while knowing that this contradicts the Shari`ah, they will have imperfect Iman and will be attaining minor Kufr, Zhulm (injustice) and Fisq (flagrant violation of Islamic law). This meaning was authentically reported from Ibn `Abbas (may Allah be pleased with both of them), Mujahid and a group of Salaf (righteous predecessors) (may Allah be Merciful to them). It is also the view of AhlulSunnah walJama`ah (those adhering to the Sunnah and the Muslim main body), contrary to Khawarij (separatist group that believes committing a major sin amounts to disbelief) and Mu`tazilah (a deviant Islamic sect claiming that those who commit major sins are in a state between belief and disbelief) and those who followed their way.
Allah is the One to be sought for help and support.