The laws that Allah has laid down for His servants and has made clear in His Noble Book or upon the tongue of His Messenger (sallallaahu ‘alaihi-wasallam) – such as the laws of inheritance, the five daily prayers, zakat, fasting and so forth that Allah has made clear for His servants and concerning which the Muslim Nation ( ummah ) is in agreement – may not be opposed or changed by anyone as they have been laid down to be applied for this Nation for the time of the Prophet (sallallaahu ‘alaihi-wasallam) and after him until the Hour [of Judgement] is established.
From those laws is the giving of preference [in inheritance] to male children over female children, and grandchildren, and full brothers and half brothers from the father. Allah has made this clear in His Noble Book and there is a consensus of the Muslim scholars upon it. It is, therefore, obligatory to act upon it with faith and belief. If a person alleges that something different from what the Shariah has stated is better or more suitable, then he is a disbeliever. Similarly, anyone who says that it is permissible to go against the Shariah is also a disbeliever. This is because he is opposing Allah and His Messenger (sallallaahu ‘alaihi-wasallam), as well as the consensus of the ( ummah.) it is upon the ruler to ask him to repent if he is a Muslim. If he repents [that is accepted from him]. If he does not repent, then he must be killed as a disbelieving, apostate from Islam. This is because the Prophet (sallallaahu ‘alaihi-wasallam) said,
''Whoever changes his religion is to be killed." 
We ask Allah for safety and for all Muslims safety from the misguidance and trials and from differing from the pure Shariah.
 Recorded by al-Bukhari, Ahmed, Abu Dawud, al-Nasai, al-Tirmidhi and ibn Majah.