Against Celsus 3.65

He thinks that we say such things to encourage sinners because we are unable to win over any man who is truly good and righteous, and that for this reason we open the gates to the most unholy and abandoned. But if anyone considers our gathering fairly, we can show more who were converted from a life not very bad than from the most abandoned sins. For those conscious of better things in themselves, praying that what is proclaimed about God's reward for the better is true, are naturally more ready to assent to what is said than those who have lived very wickedly, who are prevented by their very conscience from accepting that they will be punished by the Judge of all with a punishment that would befit one who has sinned so greatly, and would not be inflicted contrary to right reason by the Judge of all. And sometimes, even if the utterly abandoned wish to accept the teaching about punishment, because of the hope of repentance, being persistently steeped in the habit of sinning, they are held back, as though dyed fast by wickedness and no longer able to depart from it easily for a settled life according to right reason. Celsus too perceived this, and somehow says in what follows: “And indeed it is surely clear to everyone that no one could wholly change those who are by nature inclined and accustomed to sin, not even by punishing them, let alone by pitying them; for to change nature completely is extremely difficult. But those without sin are better partners in life.”