I took this from Steve McVey's book, "Grace Amazing".
"Watchman Nee once asked a class of children, 'Who is a sinner?' and their immediate reply was, 'One who sins.' He responded, 'Yes, one who sins is a sinner, but the fact that he sins is merely the evidence that he is already a sinner; it is not the cause. One who sins is a sinner, but it is equally true that one who does not sin, if he is of Adams race, is a sinner too, and in need of redemption. Do you follow me? There are bad sinners and good sinners, there are moral sinners and there are corrupt sinners, but they are all alike sinners.' "