What is the ruling of applying man-made laws? Can we charge the ruler who rules with man-made laws with disbelief?

In the name of Allah, the All-Merciful, the Mercy-giving. This issue is problematic and there has been much ado about it. In the past century fatwas were given in this regard. The issue should be dealt with in detail.
First, it is undoubtedly prohibited and an enormous sin to rule with man-made laws, and there are Shari`ah texts contrary to implementing these laws. In the Quran we read, “And judge between them by what Allah has sent down. Nor are you to follow their whims.” [5:49] “Is it, then, the judgment of ignorance that they seek? Yet, who renders a fairer judgment than Allah to a people who have certainty?” [5:50]
As for the charge of disbelief, this is something that cannot be definitely decided unless, along with ruling with these laws, there is explicit derision, degradation or belittling of the status of the Shari`ah. One says, for example, that the Shari`ah is not suitable to be applied, or similar words. But if one believes that the Shari`ah is true and everything else is not true, enacting such laws is not enough reason for the charge of disbelief, as it may be due to his inability, ignorance or imitation of others. Therefore, Ibn `Abbas (may Allah be pleased with them) said about the Quranic verse that reads, “And whoever does not rule by what Allah has sent down – then such as these are the non-muslims,” [5:44] that this is a lesser disbelief, and about the verse that reads, ” And whoever does not rule by what Allah has sent down – then such as these are the ungodly,” [5:47] that this is a lesser ungodliness, which means that it does not cast the person out of the fold of the religion. This is the position we adopt based on many scholarly statements including statements from Sheikh al-Islam Ibn Taymiyyah (may Allah have mercy with him).
`Adyy ibn Hatem said: I heard the Messenger of Allah (peace and blessings be upon him) reading from Bara’ah, “They have taken their rabbis and their monks as lords apart from Allah” [9:31] and he said, “They did not worship them, but if they made things lawful for them, they would deem it lawful, and if they made things unlawful for them, they would deem it unlawful.” [Reported by al-Termidhy (3095) and others] This is the indirect meaning of worshiping them. They changed the prescribed injunctions given in the name of the lawgiver insomuch that they declared as unlawful what the lawgiver made lawful and as lawful what the lawgiver made unlawful, attributing this to the Shari`ah, such as saying, for example, that the Prayer, Fasting or Zakah are not obligatory in the Shari`ah, or that committing enormous sins is permissible. But committing these enormous sins and letting others commit them is not a reason for disbelief, in itself.
This position is contrary to the position of some muftis and sheikhs in the past century who considered merely doing this as enough reason for the charge of disbelief. We verified this point in a separate study titled (al-Takfeer bi al-Hukm bi Ghayr ma Anzala Allah) in the Contemporary Fiqh Research Magazine. Besides, the charge of disbelief will lead to wars and will stir devastating mischief. It is rather better to educate people and draw their attention to the importance of the Shari`ah and the great benefits the Shari`ah provides. Many of the Muslim countries were colonized and thus they inherited the laws of the colonizers and unconsciously continued in this way, lacking the courage to change these laws.
Hence, we do not deem this as enough reason for the charge of disbelief unless it is accompanied by disparaging or deriding the Shari`ah, or by a deviant conviction. Peace and blessings be upon our Prophet Muhammad.