The Spiritual World outside the Physical World
Plato described, about 400 years before the appearance of Christ Jesus, the Myth of Er where the afterlife was depicted, which is one of early reports on near-death experiences (NDE).
Er died in a battle, but he was revived on his funeral-pyre and told others of his journey in the afterlife, "including an account of reincarnation and the celestial spheres of the astral plane. The tale includes the idea that moral people are rewarded and immoral people punished after death." (https://en.wikipedia.org/wiki/Myth_of_Er)
Dante Alighieri (1265 – 1321) also wrote the Divine Comedy, a long Italian narrative poem, displaying the state of the soul after death, presenting "an image of divine justice meted out as due punishment or reward, and describing Dante's travels through Hell, Purgatory, and Paradise or Heaven (https://en.wikipedia.org/wiki/Divine_Comedy). William Shakespeare (1564 – 1616) also wrote Hamlet, his masterpiece, handling ghosts, showing his interest in the spiritual world.
In addition, Emanuel Swedenborg (1688 – 1772), a Swedish pluralistic-Christian theologian, scientist, philosopher and mystic, wrote many books on the afterlife, Heaven and the hell (https://en.wikipedia.org/wiki/Emanuel_Swedenborg); and Johann Wolfgang von Goethe (1749 – 1832) presented Faust, a tragic play, focusing on human souls, the devil, Heaven, etc.
In Gospels, Christ Jesus seems to take it as read that the soul of a man goes into the spiritual world after his physical death in this world. Therefore, the European Christian civilization and culture are based on the notion that a man has a soul that will live in the spiritual world after his biological death in this world.
Therefore, there is no wonder that Eben Alexander III (1953 -), an American neurosurgeon and author, wrote a book on his near-death experience that happened in 2008 under medically-induced coma when treated for meningitis (https://en.wikipedia.org/wiki/Eben_Alexander_(author)).
"Alexander's second book, The Map of Heaven: How Science, Religion, and Ordinary People Are Proving the Afterlife, was published in October 2014, where he again asserted the existence of an afterlife and that consciousness is independent of the brain. Alexander framed his observations with quotations from spiritual teachers and paired them with the recent work of scientists with the aim of bridging religion and science." (https://en.wikipedia.org/wiki/Eben_Alexander_(author)#Proof_of_Heaven)
There are many people who experienced near-death-experiences in the world. According to recent research, 40% of Americans have experienced near-death experiences at the point of death or under critical conditions. Most of contents of their experiences include peaceful access to the spiritual world but they were told to return to this world and thus they were revived. Interestingly, most of them did not face judgement by the God.
Anyway, as the critical era as to whether the mankind can be allowed to avoid the end of the world seems to come closer in the 21st century, information on near-death experiences, Heaven and the hell, the God and Satan, etc. must be all the more focused on. More and more people should be given such information by the God, Angels, etc.
In my view, Satan should also interfere with this trend, sending false prophets and sorcerers with evil spirits. People should be confused or brainwashed with wrong images of the spiritual world. Otherwise, some people should all the more stick to atheism.
However, as everyone believes that he has a mind in addition to his physical body, there is no wonder that there is the spiritual world outside the physical world where we are living.
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Mark 4, King James Version
28 For the earth bringeth forth fruit of herself; first the blade, then the ear, after that the full corn in the ear.
29 But when the fruit is brought forth, immediately he putteth in the sickle, because the harvest is come.
30 And he said, Whereunto shall we liken the kingdom of God? or with what comparison shall we compare it?
31 It is like a grain of mustard seed, which, when it is sown in the earth, is less than all the seeds that be in the earth:
32 But when it is sown, it groweth up, and becometh greater than all herbs, and shooteth out great branches; so that the fowls of the air may lodge under the shadow of it.