Wheel of Sin
"To know ones sin is to have no sin; I ask you then, are you a sinner?" The 'circle of sin' is a riddle or paradox given by the washi to Rakka (and, we find out later in the story, to Reki)The problem it poses is expressed by Rakka, in that if one is concious of a sin/fault, then one is no longer at fault (in a purely personal sense, the dammage done by such actions must still be dealt with)But considering oneself no longer at fault, is one a sinner?
The answer, at least for Rakka, and to a certain extent for Reki, is that no one can overcome their sin themselves. Forgiveness is neccesary.
Notes, queries, and speculation.