Earth, Heaven, and Hell
Of all the questions posed to religion, what happens after death is perhaps the most controversial because we can’t observe it directly. My own beliefs on this matter are driven primarily by one underlying question:
What is the purpose of Earth in God’s grand design?
While we obviously can’t directly ask this question or find definite proof in the world around us, I believe an answer can be deduced from the nature of angels. Christianity has traditionally drawn a distinction between angels and the souls of the righteous dead, categorizing them as different species. While it is certainly possible the souls of aliens or other species were in heaven before the first human walked the earth, I see the difference as immaterial. If God, the author of souls, makes human souls in his image, why would other sapient souls be any different? Since the obvious answer is that there is no material difference, the logical conclusion is that the souls of the righteous dead are angels, and that in turn implies the answer to the first question:
Earth is the forge of angels.
If the purpose of Earth is to transform raw, undeveloped souls into angels as I believe, what happens after death becomes clear. Ideally, a soul is strengthened by the adversity it faces on Earth, learning from its mistakes, overcoming challenges, rising above the evil that seeks to drag it down, and ultimately ascending to join the ranks of the angels at God’s side in Heaven.
Conversely, souls which succumb to evil and reject righteousness fail to become angels. These fallen souls are called demons and discarded into Hell which need not necessarily include any additional punishment since the evil souls within will torment each other much like unattended prisoners on Earth. This does not necessarily imply there is no supremely evil being overseeing Hell because there absolutely could be, but Satan could just as easily be a metaphor for evil or an angel God tasks with testing mortals.
However, this dichotomy cannot exist without reincarnation for souls which are not adequately tested. If a child dies immediately after birth, the soul obviously hasn’t had time to develop its character either way so no judgement can be made. Thus, the only reasonable option is to give the soul another chance through reincarnation. There is also some circumstantial evidence for this in that some children seem wise beyond their years, possibly implying they were reincarnated after spending some time on Earth, especially since it seems reasonable that God would allow righteous souls to return to Earth if they felt the need to do so was worth the suffering of facing mortal life again.
Naturally, only God, the supreme and omniscient judge, can truly know if a soul deserves to go to Heaven, Hell, or be returned to Earth after death, but I believe this is the most reasonable explanation.