There is no such thing as a place of eternal damnation for sinners, and what Christians call hell is a fabrication. Only purgatory exists, which, as the name implies, is the region where, for a greater or shorter length of time, humans ‘purge themselves’ of their faults, that is to say they wash and purify themselves – and this purification is obviously accompanied by suffering.
But human beings’ evolution does not stop the moment they atone for their faults.
Humans’ true evolution takes place on earth. Since they did wrong on earth, they must return to earth to repair the damage they did there.
For having regrets and suffering do not suffice, suffering does not mend the mistakes that were made.
Humans must return to earth to repair their mistakes.
There is no other explication for reincarnation. If humans had already atoned for their sins in the hereafter, why should they have to come back down to earth again? By law, they are obliged to mend their mistakes in all the regions of the universe where their mistakes caused disorder and destruction.