The Muhaddith, Al-Imaam, Ar-Rabbaani, Muhammad Naasir ud-Deen al-Albaani (رحمه الله) wrote:
The key to the return of the glory of Islaam is:
The application of beneficial knowledge and the establishment of righteous actions.
And it is a great matter that the Muslims will not achieve except by applying the methodology of tasfiyah (purification) and tarbiyah (cultivation).
And these two are extremely important obligations.
And what is meant by the first of these matters (Tasfiyah):
Firstly: The purification of the ‘aqeedah (creed) of Islaam from that which is foreign to it of shirk, denial of the attributes of Allaah and misinterpretation of them (ta’weel), and the rejection of authentic ahadeeth (by the people) because they are connected to ‘aqeedah and their like.
Secondly: The purification of the Fiqh (understanding) of Islaam from the incorrect ijtihaadaat (deductions of legal rulings) which oppose the Book and the Sunnah and the liberation of the mind from blind following and the darkness of fanaticism.
Thirdly: The purification of the books of tafseer (commentaries of the Qur’aan), fiqh (understanding), ar-Raqaiq (softening of the hearts), and other than them from the weak (da’eef), fabricated (maudoo’), Isra’eeliaat (from the doubtful sources of Ahl al-Kitaab), and abominations (munkaraat).
And as for the other obligation (Tarbiyah):
What is needed is the cultivation of the next generation (of Muslims) upon this Islaam which is purified from everything we have mentioned, giving them the correct Islaamic Tarbiyah (cultivation) from the beginning without having any influences from the Western indoctrination of kufr.
And there is no doubt that the realization of these two obligations, requires enormous cooperative effort with sincerity between all the Muslim groups and individuals, from those who are truly concerned in building the desired Islaamic society, each one working in their field and specialization.