When we sin, we are taking and experiencing temporary āgoodā and āpleasureā that does not belong to us, that we should not rightfully have had or experienced. And to do this we are turning away from God as our friend in order to be our own provider of āgoodnessā.
When we repent, turning back to God in contrition, we are again turning to him as our goal of living, rather than that temporal good or pleasure. And He, via the Confessor, absolves us of our sin and remits the eternal punishment of Hell (when you are friends with God, there is no death).
But, there still is the fact of entering into heaven, into the presence of God as he intended you originally to enter (he intended you to enter as one who had not experienced the stolen good and pleasure - in effect, you are in possession of something that does not belong to you, which is unjust). The time in purgatory is for āequalizing yourself to be as one possessing and experiencing what He provides in justice to youā - in purgatory you will be āin wantā in such a way to balance or remove the excess ānot in wantā that you took for yourself. You will suffer a time of being āhungryā for God to balance for the time you thought you satisfied your own āhungerā with the sinful self-provision.
If somehow you have āgiven backā what you took on earth before you die, then you are suited to stand in the presence of your Father, no āhuman treasuresā brought along with you from your ill-gotten gains, because you gave them back overflowing.
This is what I have learned.
John Martin