Eventually, all beings will end up in hell, even God. Thus, to prevent such a regression, a compassionate God will step in at one point. First of all, hell can't be eternal punishment. So hell, if it exists,must be for a limited time. Then one is advanced to purgatory.
Purgatory is similar to jail.
It too must be of limited time duration, otherwise there would be an infinite regress to purgatory. Just as all animals sacrificed to the Deva Yahweh in the Old Covenant went to a special paradise, so the Lamb went to Yahweh's paradise. Yet in the Apostle's Creed, it says he descended into hell. No,we try to find the mistake and re-run it, and continue the process until we are satisfied. This way, learning can occur in the individual soul.