I agree, I've read The Silmarillion multiple times.

The Bible reference makes sense but I've always thought of it as similar to reading a history book. That's essentially what it is, a history of the beginning and the first 2 ages. Whereas The Hobbit & the trilogy are narrative accounts of a very small portion of the third age.

I read it as a young teenager while listening repeatedly to one of my few cassette tapes - Beethoven's violin concerto on one side, 5th piano concerto on the other. By the end of the book I was having trouble mentally distinguishing between book and music. The piano concerto in particular still calls to mind the true protagonists in all of Tolkien: mountains, rivers, lakes, forests and plains, rather than people.

Read Silmarillion three times, would describe it as mythology. Think Beowulf rather than Bible. Thoroughly enjoyed the world Tolkien created.