I go to AA, although I am an atheist, but I can understand your frustration with the Big Book. I used to get so irritated and annoyed when people in the meetings preached out of it as if it were some sacred text.
However . . .
I had to take a look at my reaction to a book, an inanimate object! How can an inanimate object make me so angry to the point where my peace and happiness are effected?
So I began to look at the Big Book in a different way, as it truly is: a self-help book.
I own a bookstore, and if I were to categorize the Big Book, I'd put it in the self-help section. Now, how can a self-help book make me mad? It's like getting angry over any other self-help book. And I read the Big Book like I read any other self-help book--I use the parts that ring true to me and discard the rest. To take the Big Book literally (for me) leans on "cultish" and even irrational thinking and behavior. And put into perspective, it starts to seem pretty silly too, if that makes sense.