The basic reason is that Qur’an is not only a book but also a message and mission, and the Holy Prophet raised an Ummah on the bases of this book which shall continue striving for the mission, which is its raison d’etre, till the Day of Judgment.
“Thus we have made you an Ummah, justly balanced, that you might be witnesses over the people and the Prophet a witness over yourselves.” (Al-Baqarah 2: 143)
“You are the best of Peoples, evolved for mankind, enjoining what is right, forbidding what is wrong, and believing in Allah.”
