I’ve often thought that some form of reincarnation would make sense in the plan of salvation.
We already have a form of reincarnation (at least five steps encompassing an unknown and potentially “eternal” time period) in our theology:
“Intelligences” became “spirits”. “Spirits” became “mortals”. “Mortals” die and become “spirits” again. Those “spirits” become “resurrected beings”. The ultimate goal of “resurrected beings” is becoming “Gods / gods”. Those “Gods / gods” then initiate the process in one eternal round.