The World of Tolkein

I recently purchased The World of Tolkein set of  books, mistaking them for a boxed set of LOTR. I should have read the description closer, but it was a bargain….we’ve all been there, right?! Has anyone used these guides while reading LOTR?They intrigue me, but I don’t want to rip open the plastic and commit just yet. If these books-Dictionary, Atlas, Battles, Hobbits- are just non-biased guides to deciphering Middle Earth, that would be nice, but I’m concerned because the author, David Day, does not appear to be a Christian. Thanks!