What book (bible) does Kuma always hold? Bartholomew Kuma is always seen holding this book (a bible)



What is this book? 

EDIT

What type of bible is this? Just a regular bible, a bible from the One Piece world, or what? Is he some kind of priest? His shirt has same pattern as the bible.
It's clear from the pic that it's The Bible. And I believe that there is only one Bible (content-wise). About different versions - they're all translated from the original Bible. You can get a clearer view about the different versions of Bible here.


  Kuma is an enormous man, (22'6" feet tall). He is the tallest remaining Shichibukai (being one inch shorter than former member Gekko Moriah) and is usually seen carrying a Bible.


Source: Bartholomew Kuma - The One Piece Wiki (emphasis added)

Here's a pic depicting the name of the book much more clearly.