The Spirits' Book
Book Two - The Spirit World
Chapter IV - Multiple Lives
Incarnation on Different Worlds
185. Is the physical and moral state of living beings on every globe always the same?
“No, worlds are also subject to the law of progress. Like yours, all have started out by being inferior, and the Earth will undergo a transformation similar to what has occurred on countless other worlds. It will become an earthly paradise when the people who inhabit it have become good.”
The human beings that currently populate the Earth will gradually disappear, and will be succeeded by increasingly perfect races. These transformed races will replace the current human race, as the latter succeeded others that were even more rudimentary.