Let's we choose 
Syariat Islam Is About Iman
THE ISLAMIC SHARIAT IS THE FAITH OF FAITH AND WILLING
"Sir from today I do not want to pray five times anymore!"
"Astaghfirullah! So what?"
"I just realized I've been fooled all along!"
"Fooled how !? By whom !? "
"Yes by fathers like this father! I used to think the five-hour prayer command with all the instructions commanded by the Qur'an does not exist! "
"There is! There is! "
"Where? Where ?! Try to show which of the verses that command in detail the pillars of prayer? Where is the verse that tells us to move like this and so in al-Qur'an ?? Which do we tell qunut prayer time? The verse that clearly mentions the number of rakaat prayers? "
"Uh, it's ..."
"There is not a single verse of the Qur'an that describes the detailed procedures and rukun prayer!"
"You do not!"
"Not just a prayer, later I also do not want to marry with the ceremony akad marriage as in KUA! There is no verse of the Qur'an that we are married in such a way! Is not the word of the Prophet 'you know better your world affairs!'. "
Gloss.
What do you say when someone demands such a dialogue example above? I agree that the person deserves to be stamped! That foolish man who argues for Islam to reject the teachings of Islam.
In their illusion, what does not exist in the Qur'an then it does not exist, including the obligation to uphold the caliphate. The moron above will say 'no single verse' mentions the obligation to uphold the caliphate. If such induction logic is used, then undoubtedly many Islamic laws are void. The prayer procedures in detail are missing in the Qur'an, marriage ceremonies, various muamalah such as pawnshops, debt swaps, etc.
The Qur'an is a holy book and a source of law, but it is not the only source of law. Allah SWT. also ordered the Muslims to follow the Sunnah of the Prophet Muhammad.
In addition, some scholars also set some other legal sources such as ijma, qyiyas, istihsan, mashalih mursalah, urf, etc ..
Imam ash-Shafi'i in his book of Risalah explained that the sunnah has a role to the Qur'an is to repeat and strengthen the existing laws in the Qur'an, or explain the Qur'an, or postulate as nasikh-mansukh, or bring up a law which the Qur'an does not discuss (in Ushul al-Fiqh al-Islamiy, Dr. Wahbah Zuhaili, p. 461).
This discussion is very clear and anyone who examines ushul jurisprudence must have understood it very well. The problem is then there are people who continue to provoke Islamic law around the khilafah with the excuse that there is no discussion in the Qur'an. Whereas some of the exegetes such as Imam Ibn Kathir, Imam al-Qurthubiy, or Manna 'Kholil Qaththan also cite a number of verses as the argument that obliges the umara to fulfill their people's mandate in accordance with the laws of Allah SWT.
Furthermore, they argue that when the affairs of the world are left to human reason. Especially form of state and system of government. There is no obligation to uphold the khilafah, the people may choose any system. Again this is absurd, because the Sunnah of the Prophet Muhammad. shows state and government activities such as appointing governors, warlords, financial officers in zakat, kharaj, etc. This is the real sunnah fi'liyyah which should be used as a guide in the life of the state.
Moreover, the hadith about "your world affairs" is the context in which agriculture is mubah to use any means. There is no provision in the Qur'an and as-Sunnah which describes agricultural techniques as the development of IT technology, etc. Islam entirely devotes itself to human reason for exploration. Again this is a discussion that has been sharih and wadih for anyone who deepen the problem of ushul fiqih.
The problem is not there, but in the heart; is there a spirit and belief in implementing Islamic law? Because of the Islamic laws that have been clearly mentioned by the verses of the Qur'an there is also no sign of acceptance. Haramnya usury, hudud and jinayat like qishash, the law for thieves, pembegal, in fact they ignore when it is clear there is a verse.
So this is not a scientific issue, but
a belief and a will. If there is no faith and will, no clear law will ever be done.
