Why millions of believers still take this 14 centuries old...

Why millions of believers still take this 14 centuries old book as their source of guide and salvation in their lives? How is it different from any other thousands of books penned by different authors? What is so unique about Qur’an? Is the Qur’an a book of history, or of poetry? Or is it a book about science and natural phenomena? Is it a book about Social manners and spirituality or a book about God’s Creation? Is it a book of Law? What is its general theme?…