What is Eternal?

I enjoy watching True Blood. It's full of magic, mystery and humanity. Characters in it always struggled from shits they never imagined or expected. What is right? What is wrong? Moral or Immoral? Justify or Lust? ...
During this season of True Blood, the most interesting big question is What is Eternal?
Vampires are immortal. They live through centuries and never grow old or get hurt. But technically they are dead and, most time, don't have human feelings. They are, at some points, just afterlife format like zombies. Bill told Jessica vampires still have humanity deep in their heart. It's a considerable argument. Maybe that's true for some of them. But most vampires, in my opinion, don't have humanity now, because their humanity already faded away after centuries' cruelty and loneliness. If you can't keep your own humanity last, how can you say you are eternal? It's just immortal at most.
There is another view about eternal in the show, soul of human are eternal, even though their flesh and body are gone forever. That's how Witch Antonia came back after 400 years. In this show, there may be or not be heaven after death. But there's one thing for sure that one's soul can exist forever and may communicate with the real world if he or she have unfinished business cannot be put down. Mavis's, Gran's and Antonia's souls last quite a long time.
Godric's, a vampire, also came back after his true death, because he has the most humanity among vampire, even more than lots of real human. In my eyes, Godric is the closest to eternal.