Many revelations had been made by God and committed to writing by His devotees before the advent of the Qur'an. Then what particularly distinguishes the sacred Islamic text from its forerunners? It is not just that it is complete and the other revealed books incomplete. To categorise the sacred scriptures in this way would amount to discriminating between the Prophets themselves which is certainly not right.
What then is its great distinguishing feature? There is only one. A simple, but a major one. The text of the Qur'an has never been tampered with, whereas all the other Books have long ago lost their original form and content, which has meant a serious loss of authenticity. It is this characteristic of the Qur'an its perfect state of preservation which singles it out from its predecessors as a unique vehicle for divine guidance and salvation, one which will retain its validity until Doomsday.
The preservation of the Qur'an was a laborious task requiring remarkable skill and dedication. As such, it was the most extraordinary undertaking of the age. This feat gains in importance when seen in the context of the loss of authority of previous texts which were not maintained in their pristine state. The Qur'an alone has survived as the completely preserved utterances of the Almighty.