Merriam Webster’s Dictionary
GHOST:
1 : the seat of life or intelligence : SOUL <give up the ghost> 2 : a disembodied soul ; especially : the soul of a dead person believed to be an inhabitant of the unseen world or to appear to the living in bodily likeness 3 : SPIRIT , DEMON
SOUL:
1 : the immaterial essence, animating principle, or actuating cause of an individual life 2 a : the spiritual principle embodied in human beings, all rational and spiritual beings, or the universe b capitalized Christian Science : GOD 1b 3 : a person's total self 4 a : an active or essential part b : a moving spirit : LEADER 5 a : the moral and emotional nature of human beings b : the quality that arouses emotion and sentiment c : spiritual or moral force : FERVOR 6 : PERSON 7 : EXEMPLIFICATION , PERSONIFICATION <she is the soul of integrity>
SPIRIT:
1 : an animating or vital principle held to give life to physical organisms 2 : a supernatural being or essence: as a capitalized : HOLY SPIRIT b : SOUL 2a c : an often malevolent being that is bodiless but can become visible ; specifically : GHOST 2 d : a malevolent being that enters and possesses a human being 3 : temper or disposition of mind or outlook especially when vigorous or animated <in high spirits> 4 : the immaterial intelligent or sentient part of a person
These definitions are basically congruent. It is the essence (soul or spirit) of a human being that lives eternally:
Holy Qur’an / Surah 80
17. Woe to man! How ungrateful is vital 18. Of what thing did He create him? 19. Of a small life-germ. He creates him, then proportions him, 20. Then makes the way easy for him, 21. Then He causes him to die, then assigns to him a grave, 22. Then, when He will, He raises him to life again.
Holy Qur’an / Surah 70
42. So leave them alone to plunge in vain talk and to sport, until they come face to face with that day of theirs which they are promised 43. The day when they come forth from the graves in haste, as hastening on to a goal, 44. Their eyes cast down, disgrace covering them. Such is the day which they are promised.
Bible / Luke 12
19. And I will say to my soul, Soul, thou hast much goods laid up for many years; take thine ease, eat, drink, and be merry. 20. But God said unto him, Thou fool! This night thy soul shall be required of thee: then whose shall those things be, which thou hast provided? 21. So is he that layeth up treasure for himself, and is not rich toward God.
According to these verses, all human souls are removed from their dead carcasses. This soul removal is permanent or final. A recent convert to the religious - spiritual world is the renowned neurosurgeon Dr. Eben Alexander. He is alleged to have been in a coma for 7 straight days. He shared his otherworldly experience with Newsweek Magazine in 2012. Here is a verbatim quote from Dr. Alexander:
“My synapses, the spaces between the neurons of the brain that support the electrochemical activity that makes the brain function, were not simply compromised during my experience. They were stopped. Only isolated pockets of deep cortical neurons were still sputtering, but no broad networks capable of generating anything like what we call “consciousness.” The E. coli bacteria that flooded my brain during my illness made sure of that. My doctors have told me that according to all the brain tests they were doing, there was no way that any of the functions including vision, hearing, emotion, memory, language, or logic could possibly have been intact. That’s why, just as I now no longer doubt the existence of the world of expanded consciousness that NDE subjects, mystics, meditators, and countless other people have described for centuries, I also feel that my experience adds something new to those stories. It supplies a definitive new form of evidence that consciousness can exist beyond the body.”
[The Science of Heaven, By Dr. Eben Alexander, on 11/18/12 at 10:00PM, Newsweek Magazine]
Dr. Eben Alexander served on the faculty of Harvard Medical School for almost 15 years, achieving the rank of associate professor by 1994. He has helped to promote the development of stereotactic radiosurgery, intraoperative MR imaging and MRI-guided focused ultrasound surgery in neurosurgery. Dr. Alexander currently practices with a private neurosurgical group in Lynchburg, Virginia and travels extensively making presentations about revelations from his coma experience that elucidates the nature of consciousness. His books have sold millions of copies. It is refreshing to have an advocate for the realm unseen who can articulate scientific jargon (mumbo-jumbo) in defense of religious believers worldwide. There are a few scientists who aren’t egocentric heathens it would seem. In fact, some scientists have gone as far as to add paranormal science departments to a few of their universities: University of Virginia, University of Arizona, University of Edinburg, Goldsmith’s University of London, University of Amsterdam, and others.