Here Dante has entered the Earthly Paradise: Eden. The state man was supposed to live in always. Where all was created as Good and lived for Good. But through man’s fault (man and woman) we fell and chose grief and toil.
Here Matelda speaks to Dante about the Earthly Paradise but also the two rivers: Lethe and Eunoe.
“For on this side the stream descends with power to take away all memory of sin, but on the other side it will restore all memory of good deeds. Hence this is called Lethe ‘Forgetfulness’ and that, Eunoe, ‘Good Memories’, which it will not bring unless You taste of Lethe first; and yet its taste surpasses all.”
In all of human history, we have transgressed in all aspects of our lives. To the repentant, a grace is given, one, to turn away from sin, two, to be washed clean of the stain of sin. This includes the memory of it as well. In the Psalms it is said many times wipe the memory of my sin away (paraphrase). And the other grace is the memory of all the Good one has done by the grace of God. Why can we still accomplish good, even though we are fallen? Because God made us in His image and all that was made was good (see Genesis 1 and 2). Yet, we must be cleansed as Dante was going through the fire that renews the body, the entire being: soul. And purified in our minds of the stain of sin. Then we can stand before God, amidst the holy.
For now, we carry around the burden in body and mind of our sin. Hopefully, the load gets lighter as we follow and commit to Christ. One day the memory of our sin will be expunged forever. It seems the reality, according to Dante, and the Christian faith, one will carry the burden for eternity or only for a time and then be set free of this burden and stand before God (at the same time Unity and Trinity) similar to His Son Jesus Christ.