When the soul of man leaves the body and can relate directly to spiritual essences–thus becoming altogether spiritual, with no more than fragmented memories of having been connected with the body–then in the course of things, all that this soul had done in life casts it into its right form on the level appropriate to it in the life after death.
And therefore the soul of the sinner descends, as it is symbolically expressed, to Hell.
In other words, the soul now finds itself wholly within the world-domain of the subversive angels whom it, as a sinner, created.
And there is no refuge from them, for these creatures encompass the soul completely and keep punishing it with full, exacting punishment for having produced them, for having caused the existence of those same angels.
And as long as the just measure of anguish is not exhausted, this soul remains in Hell, which is to say, the soul is punished not by something extraneous but by that manifestation of evil it itself created according to its level and according to its essence.
Only after the soul passes through the sickness, torment, and pain of the spiritual existence of its own self-produced evil, only then can it reach a higher level of being in accordance with its correct state and in accordance with the essence of the good it created.
–Rabbi Adin Steinsaltz
From Chapter 1, "Worlds," in The Thirteen Petalled Rose by Rabbi Adin Steinsaltz