If the spirit is immortal, why shouldn't it be possible or desirable to transfer this quality to the flesh?
Think of how much you could learn if your life could be extended at least far beyond what is considered normal today. Projects could be pursued that just take more than a lifetime to complete. Soul lectures could be learned far more effectively than by starting from scratch again and again in the course of so many reincarnations.
Human beings actually used to live many hundred years in lost civilizations like Lemuria and Atlantis (of course, we won't even agree on their existence, Nungali...). This is being reflected in the bible telling us about the early patriarchs reaching an age of nearly 1,000 years. And similar claims of long life spans are found in the secular literature of several ancient cultures (including the Babylonians, Greeks, Romans, Indians, and Chinese).
Only when humans gradually fell from their original state of cosmic harmony did their lives get shorter and shorter.
I will agree on the existence of a culture or civilisation if any proof of its evidence can be shown. Anthropologically and archaeologically I am fascinated by such stuff ... but one has to have something , < grasps at thin air repeatedly > to study .... like what has been turning up at Orkney recently !
Sorry folks, no space ships, ray guns, levitations , immortality ...... but then again, I aint chasing that stuff.
But do let me know if any new evidence shows up .