[1 of 3] Swedenborg (1688-1772, Sweden): primary subject "Afterlife, harmony enforced in" (search under Outer Life/Doctrine, Rites, Scriptures)": source "Divine Providence": detail "Section 227[4]"
If evil cannot be separated from good and good from evil, a person can be neither in heaven nor in hell. Everyone must be in one or the other; he cannot be in both; for so he would be now in heaven and now in hell; and in heaven he would act in hell's favor and in hell act in heaven's favor. He would thus destroy the life of all around him, heavenly life among the angels and infernal life among the devils; as a result everyone's life would perish. For everyone must live his own life; no one lives a life foreign to his own, still less one opposed to it. Hence, in every man after death, when he becomes a spirit or a spiritual being, the Lord separates good from evil and evil from good, good from evil in those who are inwardly in evil, and evil from good in those inwardly in good. This accords with his own words:
 "To everyone who has, shall be given, that he may abound, and from him who has not, shall even what he has be taken away" [Matt. 13:12; 25:29; Mark 4:25; Luke 8:18; 19:26].

[2 of 3] Swedenborg (1688-1772, Sweden): primary subject "Afterlife, stages in" (search under Afterlife/Afterlife, Heaven, Hell)": source "Spiritual Experiences, vol.4": detail "Section 4689 - 4690"
All who come in the other life are by degrees let back into the life that they had in the world, and in fact with their outer elements and full intellectual power almost as they were there. But by degrees their outer intellectual powers are taken away, and they are let into their own nature, the evil into their own evil, and the good into their own good. The former are then sent to hell, the latter raised to heaven.
 Some complained when they saw the ability to understand external matters that they had in the world taken away, and they argued about why this is so. But in reply it was said that otherwise, by virtue of their understanding they would be in heaven, and by virtue of their will in hell, which would be a source of confusion. And if their outward understanding remained, then they would use it for supporting evils— so that evil might be in control and the rational faculty its servant. So too they would appear to be angels of light and would mislead the simple who are in the entrance to heaven and not yet prepared, and so would talk them into evils and entirely take away all possibility of their improvement.
 And in this way they would also steal from heaven the support upon which it rests, for those who are involved in the lowest matters are like supporting posts. From this is clear that the Divine order is that all be let into their own nature, which they had acquired for themselves in the world, and that they come into this, their own nature, when outer things are laid aside, and they are then left to what is within them, thus to their inner will, or what is the same, their own love.

[3 of 3] Swedenborg (1688-1772, Sweden): primary subject "Afterlife" (search under Afterlife/Afterlife, Heaven, Hell)": source "Apocalypse Explained, vol.3": detail "Section 535"
Man must be either in heaven or in hell, as he is not allowed to hang between both.