Every material object, sentient or insentient, radiates energy into its surroundings and receives energy for its environment.<quoted text>
This all sounds reasonable enough and I'm inclined to agree.
After death, it's reasonable to suppose that part of the energy would be used up to decompose the body and part would radiate into the surroundings.
Life after death as a sentient entity appears unlikely since once the brain's electrical field leaves the body, assuming it does so after death, the causal contact of the electrical field with the brain is snapped and so it's most likely that the sentience dies out (remembering that sentience is an activity of complex neuronal networking) and the little sentience that's left over as part of the exited electrical field that soon gets extinguished unless this field with its remnant sentience merges with the energy field of a living organism - in such a case it could be possible for it to continue its existence in the neuronal energy field of the living person.
All said and done, the bottom line is this - sentience, life or consciousness are products of matter in various stages of organization.
There's nothing mystical about anything.