Thus Spake Zarathustra: A Book for All and None (also translated as Thus Spoke Zarathustra) is a book written during the 1880s by the German philosopher, Friedrich Nietzsche.

The title name Thus Spake Zarathustra, is meant to be ironic and cynical, like morbid sarcasm; and is suggestive of the apprehensive atmosphere the book displays. It explains why Zarathustra turned himself into a Prophet, during an era where God is dead (metaphor) in order to quell and stop disorder and confusion in the Middle East.

Thus Spake Zarathustra is a very good read (whether you are Atheist or believer).
Hard to categorise, the work is a treatise on philosophy, a masterly work of literature, in parts a collection of poetry and in others a parody of and amendment to the Bible.