Many religions believe in afterlife but after death of physical body. Some are convinced that hell or heaven or some space in which are soul cleaning from sins existing unseen to the eyes but that they are representing the reality.

But what about this, that there are some secret way to be immortal in physical body, have young body which never get old and seriously sick to be threatened to die.

I think in ancient times there are some knowledge about spiritual initiations which led humans to be immortal in physical body, and maybe still some fragments of that knowledge exist and can be fully recovered.

There some examples in bible of long living human beings who lived about 1000 years. Some of us give critiques that their calendar and calculations of number of years which they lived was misunderstanding. 1000 years is not still immortality.

If somebody offers you Immortality in physical body that you have young vital body and 100% chance of survival but that you must first go trough dangerous and painful process in which you can lose yourself process to prove that you are worthy of it would you accept that challenge.