The renewal of Islamic civilisation requires the rehabilitation of knowledge. For the Muslim way of life is based on the knowledge of the Muslim way of life. If that knowledge is corrupted, the way of life based on that knowledge will also be tainted. Faced with the necessity to acquire present-day knowledge, Muslims recommend the Islamization of knowledge. However, what is required is the rehabilitation rather than the Islamization of knowledge. Islam was revealed to be adopted by people. An abstract formula cannot become a Muslim. Recourse to the teaching of abrogation resulted in a corruption of the knowledge of revelation. Hence, the theory of abrogation requires rethinking. The theory of abrogation is controversial, and with reason. For the application of this theory has enabled tampering with the teaching of revelation. There is a tendency to assert that the former revelations were corrupted, and that Islam escaped the bane of corruption. What is missed is that even if the text of revelation remains unchanged, its knowledge may still be corrupted. This is what appears to have transpired, when a few verses of the Quran were pronounced "abrogated." To declare a verse of revelation to be abrogated is to ask believers to reject a part of revelation, to ask believers to disbelieve in parts of revelation. Is a request of this kind in keeping with the teaching of revelation? Many jurists rejected abrogation. These encompass Fazlur Rahman, Muhammad Asad, Muhammad 'Abduh, Rashid Rida, and Muhammad Ghazali. Abu Muslim al Isfahani also rejected the theory of abrogation. The theory of abrogation was adopted to enable an articulation of Islam to justify expeditions to enlarge the "realm of peace" at the expense of the "realm of war," an early variant of the "clash of civilizations" thesis. The concept of abrogation was adopted to re-interpret Islam in a manner that would justify building an empire. The teaching of abrogation achieved a political purpose: it facilitated the emergence of "political Islam." Unfortunately, the application of abrogation tainted the knowledge of revelation. This had adverse effects on the Muslim empire. That exegetes agreed to the utilisation of the theory of abrogation in the first place, to put themselves at the service of a political agenda, is regrettable. It reveals the plateau which exegesis reached by allowing itself to be used for political ends. It betrays its endorsement of the political authorities of the day. The theory of abrogation became entrenched after rule of the Mu'tazilites (813 to 849). With the emergence of the prophetic traditions, Islam became "traditional," based on tradition and revelation. The abrogation of the peace verses by the ayah as-sayf transformed the knowledge of revelation. It transformed the religion of peace into a rationale for empire-building in the "clash" between the "the realm of peace" at the expense of the "realm of war," a process fuelled by political aspiration. The effects of the alteration of the knowledge of revelation are apparent in penal law, where penalties from traditions replaced those prescribed by revelation. The penalties in the traditions flouted the penalties prescribed by revelation. The words of persons "abrogated" the rulings of God. The application of abrogation by tradition flouted of a fundamental rule of jurisprudence, which is that revelation is the chief authority that may not be abrogated by an alternative authority. The renewal of Islam requires the rehabilitation of knowledge, in particular, the knowledge of revelation. Hence, what is required is a rehabilitation rather than the Islamization of knowledge. This requires the engagement of reason. For revelation was "eclipsed" by tradition, facilitated by the teaching of abrogation. Exegesis requires freeing from unwarranted accretions and problematic procedures. The rehabilitation of exegesis, however, requires the utilisation and therefore the rehabilitation of reason.