Do all religions have a holy book?

All require some form of guidance and these books are not interpreted the same or are amended to suite the faith one is creating.

- Very many religions in the World today have no holy book
- A holy book is no guarantee that a religion will not change
- Religious teachings are passed down orally in very many religions

Truth is self evident... and before books were printed it was usually presented by cultural beliefs and "word of mouth". Not all religions have a "holy" book, and some that do have had them changed to reflect various religious beliefs.

Naah

No. ALL Christian and Jewish religions do. Lots of fake god religions, like mon-day, was named for their fake moon-god, day to worship. I have not heard of a book for them.
Look at the religion of "Atheism", everything they paid to have made-up after the Atheists LOST in the Supreme Court; and GOD WON were Ordered to be tested and by 2007 ALL were discovered to be Fakes! Most of what Atheists had claimed to be "millions of years old" were Discovered to be New BONES! Dried Blood even still in them! Some fossils, yet none tested to be more then 6,000 years old; same as the Bible states! There certainly is Not anything honest or "holy" in the religion of Atheism! Can any Atheist state how any of their theory (only) could have developed from one part to the next? Science dose Not know!