Let me see if I remember this story. When a person- or the land- is overrun by filth, she must work long and hard for the salvation of God. After the ark is completed, God purifies the person in a great torrent of tears of repentance, which floods the person's soul and drowns all that which is filthy. That which struggled to praise the Lord and live right is lifted up up up above the waters, to the point where all that remains is the person's pure presence, with water below, and the vast sky of God above. When the tears subside, a beautiful rainbow of hope covers the land in a show of love.