Gregory of Nyssa

The bride further speaks to her pupils of an amazing fact about herself in order that we might learn of the bridegroom's immense love for humankind who added beauty to the beloved [bride] through such love. "Do not marvel," she says, "that righteousness has loved me." Although I have become dark through sin and have dwelt in gloom by my deeds, the bridegroom made me beautiful through his love, having exchanged his very own beauty for my disgrace. After taking the filth of my sins upon himself, he allowed me to share his own purity, and filled me with his beauty. He who first made me lovely from my own repulsiveness has showed his love for me.…The bride says, although the beauty given to me by being loved by righteousness now shines forth, I still realize that in the beginning I was not radiant but black. My former life has created this dark, shadowy appearance. Although I am black, I am now this beautiful form, for the image of darkness has been transformed into beauty.…
Then the text adds further words for strengthening the minds of its pupils. The cause of darkness is not ascribed to the Creator, but its origin is attributed to the free will of each person.