In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Islaam is not a set of ideas, rather it is a divine revelation sent down – by the Lord of universe – in the Magnificent Qur’aan and the (authentic) Sunnah of the noble Messenger [peace and blessings of Allaah be upon him] – the Messenger who never speaks based on his desires, rather [إِنۡ هُوَ إِلَّا وَحۡىٌ۬ يُوحَىٰ – It (i.e. the Qur’aan and the authentic Sunnah conveyed by the Messenger) is nothing else but a revelation that is inspired].
As for an idea, it can be (rejected, disapproved etc) and debated, and it may be correct or incorrect. Therefore, it is not permissible to associate Islam with the term ‘Idea’ because it is something specifically attributed to the creation [i.e. humankind and Jinn]. An idea can either be correct or wrong, (but) as for the Sharee’ah [i.e. the sound divine law, creed, acts of worship conveyed by the final Messenger from the Qur’an and the authentic Sunnah], it is infallible.
Likewise, it is not to be said, “Islamic idea”, because the scholar who has reached the level of Ijtihaad is restricted by the pure Sharee’ah, so he is not allowed to contemplate [outside the confines of the sound divine revelation revealed by the All-Knower (Allaah)] and then legislate; rather he searches and follows the legislated Islamic path of (sound) Ijtihaad in order to derive rulings. [Ref 1]
Amr bin Al-Aas [may Allaah be pleased with him] narrated that he heard Allaah’s Messenger [peace and blessings of Allaah be upon him], ‘’If a Mujtahid gives a verdict according to the best of his knowledge and his verdict is correct, he will receive a double reward, and if he gives a verdict according to the best of his knowledge and his verdict is wrong, even then he will get a reward.’’ [Bukhari Number 7352]
Few Masaa’il From This Hadeeth
[a] A Mujtahid is not deprived of reward. [b] The judgement of a non-Mujtahid is different from that of a Mujtahid. Shaikhul Islaam Ibn Taymiyyah [may Allaah have mercy upon him] said that the one who speaks about the religion without knowledge and out of ignorance (is guilty of) lying and sinning. The one who intentionally speaks to oppose the truth is threatened with entry into the fire of hell, as opposed to the affair of the one who speaks based on permissible Ijtihaad, for indeed he strives, fears Allaah as much as he is able, desires to seek knowledge as much as he was able, speaks for the sake of Allaah, knows the stronger proof and speaks based on that. This person is given two rewards if he is correct; but if he is mistaken, he receives one reward. [c] A Mujtahid can be correct or mistaken. [Ref 2]
Al-Allaamah Rabee Bin Haadee [may Allaah preserve him] said: ”We do not say that there are people of ijtihaad amongst ahlul bidah (the proponents of religious innovations) because they are followers of desires, and Allaah and His Messenger have testified to this. The misguided innovator stirs up discord and errs, and then says to you, “This is ijtihaad”. When Hikmatiyaar and the misguided parties (in Afghanistan) murdered Shaikh Jameel Ur-Rahmaan, they said: “This is ijtihaad”. They [proponents of religious innovations] do not fall into an affair of misguidance or a calamity except that they say, “This is ijtihaad.” This is (tantamount) to diluting Islaam, falsehood, misguidance, bidah and confounding truth with falsehood when the mistakes of the (true and qualified scholars of ijtihaad)- for which they are rewarded- are placed at the same level with innovation in religious affairs about which the Messenger [peace and blessings of Allaah be upon him] declared to be destined for the hell fire. [Ref 3]
[Ref 1: An Excerpt from ‘Mu’jam Al-Manaahiy Lil-Laf’dhiyyah’. pages 430-431. Slightly paraphrased. Publisher: Daarul Aasimah. 3rd Edition 1417 AH (1996)]
[Ref 2: Al-Arba’oona Hadeethaa Fee Usoolil Fiqh. pages 32-33. slightly paraphrased]
[Ref 3: An Excerpt from ‘Ajwibatul Allaamatush Shaikh Rabee Bin Haadee Al Madkhalee Alaa As-ilah Abee Rawaaha Al-Manhajiyyah page: 20];