Need a book suggestion

Hello everyone!!

I am reading CIRCE by Madeline Miller and there is line on one of the last pages where she was wondering about her mortal son going to underworld after death and then she states “ i could never go there, for gods are the opposite of death”

And after reading this line I instantly wanted to read something like that something opposite to gods, something opposite to life.

Now, I am wondering if any of you would suggest me a fiction novel where I could read about the life after death or related experiences. Something other worldly but not godly.

Thanks.