'No one who considers his frailty would dare to attribute to his own strength his chastity and innocence, so that he has less cause to love you - as if he had less need of your mercy by which you forgive the sins of those converted to you. If man is called by you, follows your voice, and has avoided doing those acts which I am recalling and avowing in my own life, he should not mock the healing of a sick man by the Physician, whose help has kept him from falling sick, or at least enabled him to be less gravely ill. He should not love you less, indeed even more; for he sees that the one who delivered me from the great sickness of my sins is also he through whom he may see that he himself has not been the victim of the same great sicknesses.'
Augustine of Hippo, Confessions, p.32.