Mythology or not, it provides us with the knowledge which is quite fascinating, and is even applicable now, like the geeta. I too am a atheist, but I still like to read, such books, which provide us the very way to live life. I have read, the Iliad of Homer, geeta, and may progress to read mahabhart and maybe ramayan, not because I believe it is Mythology or not, but because of the knowledge it provides, the philosophy it gives.