The concept here is very interesting. Even if you do not have a use for the "pantheon" he presents, the manner of its presentation -- the idea of having explorers stumble across a whole different way of worshiping -- is a great thing to introduce to your game. I also like that the authors added comments from "reviewers" on just how heretical the beliefs are to their own beliefs.
The layout's background colors make some text a little harder to read. Other than that, this is an excellent tool to help you think about how your characters should react to finding a new faith out there in the world beyond their own faith's reach. I heartily recommend it.
I rather like this campaign resource. It's not that long, but it does give a good example of using a journal format to add story and context to describing and fleshing-out campaigns. Five stars - I picked it up on discount and was entertained enough to read it straight through.