I sometimes think of it like this. The afterlife and Ghosts. It all has to do with dimensional space and time. If someone passes, Where does that person pass on too? Some people believe it just ends. And Hey. That's possible. But. There are a few physical laws that could still point toward a (something) after this life ends. For instance. If time does turn out to be relative to a point. Then time can be twisted, distorted.. An example would be. If time could be twisted and manipulated to a point when someone who has passed away at one point, was alive in another. The principal is. Just because that person doesn't exist in the present, Doesn't mean the person didn't exist. and in the grander scheme, From the point of view of a neutrino or a photon. to ever exist is to exist forever. Someone who could travel from one point in time to another, Like a photon or neutrino. Could visit that person any time they wished. So, The person exists forever in time and space from the point of view of that Neutrino or photon. That may be all it takes for something to be eternal, to simply, no matter how briefly exist. If you think about it.