“Will the reign of goodness ever be established upon the earth?
Goodness will reign upon the earth when, among the spirits who come to dwell in it, the good shall be more numerous than the bad; for they will then bring in the Reign of Love and Justice, which are the source of Good and of Happiness. It is through Moral progress and practical conformity with the Laws of God, that men will attract to the earth Good Spirits, who will keep bad ones away from it; but the latter will not definitively quit the earth until its people shall be completely purified from pride and selfishness.
The transformation of the human race has been predicted from the most ancient times, and you are now approaching the period when it is destined to take place. All those among you who are labouring to advance the progress of mankind are helping to hasten this transformation, which will be effected through the incarnation, in your earth, of Spirits of Higher Degree, who will constitute a new population, of greater Moral advancement than the human races they will gradually have replaced. The spirits of the wicked people who are mowed down each day by death, and of all who endeavour to arrest the onward movement, will be excluded from the earth, and compelled to incarnate themselves elsewhere; for they would be out of place among those nobler races of Human Beings, whose felicity would be impaired by their presence among them. They will be sent into never worlds, less advanced than the earth, and will therein fulfill hard and laborious missions, which will furnish them with the means of advancing, while contributing also to the advancement of their brethren of those younger worlds, less advanced than themselves, do you not see, in this exclusion of backward spirits from the transformed and regenerated earth, the true significance of the sublime myth of the driving out of the first pair from the garden of Eden? And do you not also see, in the advent of the human race upon the earth, under the conditions of such an exile, and bringing within itself the germs of its passions and the evidences of its primitive inferiority, the real meaning of that other myth, no less sublime, of the fall of those first parents, entailing the sinfulness of their descendants? ‘Original sin,’ considered from this point of view, is seen to consist in the imperfection of human nature; and each of the spirits subsequently incarnated in the human race is therefore responsible only for his own imperfection and his own wrong-doing, and not for those of his forefathers.
Devote yourselves, then, with zeal and courage to the great work of regeneration, all you who are processed of faith and good will; you will reap a hundredfold for all the seed you sow. Woe to those who close their eyes against the light; for they will have condemned themselves to long ages of darkness and sorrow! Woe to those who centre their enjoyment in the pleasures of the earthly life; for they will undergo privations more numerous than their present pleasures! And woe, above all, to the selfish; for they will find none to aid them in bearing the burden of their future misery!”,
in The Spirits’ Book, Allan Kardec, answer to the question number 1019.