Why is Islam the Last Prophetic Message? 
Islam is the title of man-Allah relationship since the beginning of creation and the rise of human societies. One can say that the Qur’ān has the entire teachings of the greatest prophets, i.e., ˀUlu l-‘Azm, who are the carriers of the most important messages. If Moses and Jesus were still alive, the statements of the Qur’ān would be sufficient for them on faith and ethics. As for the cases of laws, their disparity is of little value. Islam delivered by Prophet Muḩammad and followed by people is the last form of Revelation and the general message for all races and generations until the Last Day. All past prophets were local and limited in time and place. In other words, they were sent for specific people and in limited places. However, only the message of Prophet Muḩammad is universal and unprecedented. The underlying reason is that, after giving humankind the last commandments of the divine revelation, Islam requires them to use their minds for the best understanding, judgment, and knowledge of what is right and beneficial. The end of the age of revelation marks the beginning of the age of reason as explained in detail in our book “Fiqh us-Sīrah” (Understanding the Prophet's Biography).
The Prophet of Islam (Allah's peace and blessings be upon him) laid the foundations of faith, worship, and ethics, providing the decisive texts for the organization of human life and communities. These solid foundations and directives do not differ from time to another. What is beyond that is entrusted to human mind to show creativity, such as areas related to sciences, principles of development, regulations of civil life, and phases of civilization. In these areas, human minds act freely without restrictions.
Shūra (consultation), for example, is a religious principle meant to prevent political tyranny and idolization of individuals in order to enable peoples to take charge of their affairs. In this area, the human mind can draft constitutions to achieve this aim. Similarly, justice is a religious principle to prevent offences and injustices. It is up to the human minds to enact laws and found courts to achieve this purpose at the administrative, social, and economic levels. Likewise, Jihad is a religious principle to protect faith and prevent sedition and disorder, and this is achieved through various means, such as land forces, navy, or air forces.
The same goes true for the laws of traffic fines, cheating, anger, forgery, usury, treason, embezzlement, misappropriation of orphan's property, and escape from war, among many other crimes. In some cases, it is the duty of the human minds to interfere and address consequences, such as the new cases without precedents at the time of the Prophets, e.g., space invasion, satellite warfare, and even some human ordinary activities on earth. Some serious issues forced the governments to exercise powers in a manner unfamiliar to the history of human life. Only watchful minds can accomplish this mission, backed with faith and righteousness.
It is not difficult for Allah to send another prophet. However, it is vanity to send another prophet to convey a fraction of the same previous message or repeat it. That is why it is sufficient, according to the decree of Allah, for humanity to take the revealed book and the Prophet's Wisdom as their guide to the Last Day. If the inheritors of Islam, leaders and scholars, did their duty honestly, there would be no need for such a question: Why was Islam the seal of religions? Actually, this question is the product of moral vacuum observed in the life of Muslim people, especially in recent times. No doubt, the Muslim nation lost the ability to lead itself, due to cultural and political corruption. It is no wonder then that it cannot lead the world or provide a model of human leadership for the world to follow. People of sound minds refuse backwardness, retardation, and restrictions on the world's intellectual and civilized activities. If Islam had been a backward way of life or a barrier to civilization, we would not have accepted it a as a religion that refines its followers. Actually, Islam is meant to develop the entire humanity.
The real jurists of Islam state that Islamic Laws absolutely embody and seek for justice, mercy, virtues, freedom, and benefit-achieving! These are the goals of human life. Facts are invariable. Likewise, the divine unity is a distinct and unchangeable attribute of the Lord. It is thus an inescapable fact that man shall follow His Lord. The progress of civilization does not mean that man can do without Allah or without prayers and supplication. This is evident in fields related to morals and human relationship. It is unfortunate that the People of the Scripture (the Jews and the Christians) thought that religion was merely composed of acts, ceremonies, and sacred illusions. Conversely, Islam is a relationship with Allah. Religion ordains perfect acts. Accordingly, one who is sincere, pious, and good will not suffer any injustices. Allah says, “They say, ‘None shall enter the garden (or paradise) except he who is a Jew or a Christian’. These are their vain desires. Say, ‘Bring your proof if you are truthful’. Yes! Whoever submits himself entirely to Allah and he is the doer of good (to others) he has his reward from his Lord, and there is no fear for him, nor shall he grieve.”(Qur’ān, 2:111-112).
How should these facts not conclude the message of religion? Allah, the Lord of the creation, commands all people in every time and place to worship Him sincerely and obey His commands, which in turn cause them to lead a peaceful and safe life in this world and the Hereafter. What can one say after that? What should a prophet, if any, after Muḩammad say? However, there are subsidiary detailed laws related strongly to this foundation that cannot be ignored! It is important to note the following:
First: Muslim thought has been weakened by extraneous heresies and myths introduced to religion, which t are not acceptable at all. Unfortunately, such bad thoughts interposed in religion at times get more circulation than some facts of religion. For Islamic facts to last, it should be free from such deceit.
Second: The order of the branches of faith has recklessly been reconsidered by some Muslims. To them, the pillars of faith have become voluntary and vice versa. Similarly, some reasonable issues are seen as parts of the escalatory and the rulings of the lawful and unlawful are subjected to local customs. This has happened despite of the fact that Sharia ruling expresses the command of Allah related to the competent people; no ruling is there if there is no command. Islam has always been, and shall eternally remain to be the religion with which Allah is pleased. It is in the interest of humanity to adhere to this great religion.
 Muḩammad El-Ghazāli, “A Hundred Questions on Islam”, Al-Azhar Center for Translation (ACT), 2017, p. 5.