To Oceanus
1. I never supposed, son Oceanus, that the clemency of the Emperor would be assailed by criminals, or that persons just released from prison would after their own experience of its filth and fetters complain of relaxations allowed to others. In the gospel he who envies another's salvation is thus addressed: “Friend, is your eye evil because I am good?” “God has concluded them all in sin that he might have mercy upon all.” “When sin abounded grace did much more abound.” The first born of Egypt are slain and not even a beast belonging to Israel is left behind in Egypt. The heresy of the Cainites rises before me and the once slain viper lifts up its shattered head, destroying not partially as most often hitherto but altogether the mystery of Christ. This heresy declares that there are some sins which Christ cannot cleanse with His blood, and that the scars left by old transgressions on the body and the soul are sometimes so deep that they cannot be effaced by the remedy which He supplies. What else is this but to say that Christ has died in vain? He has indeed died in vain if there are any whom He cannot make alive. When John the Baptist points to Christ and says: “Behold the lamb of God which takes away the sins of the world” he utters a falsehood if after all there are persons living whose sins Christ has not taken away. For either it must be shown that they are not of the world whom the grace of Christ thus ignores: or, if it be admitted that they are of the world, we have to choose between the horns of a dilemma. Either they have been delivered from their sins, in which case the power of Christ to save all men is proved; or they remain undelivered and as it were still under the charge of misdoing, in which case Christ is proved to be powerless. But far be it from us to believe of the Almighty that He is powerless in anything. For “what things soever the Father does, these also does the Son likewise.” To ascribe weakness to the Son is to ascribe it to the Father also. The shepherd carries the whole sheep and not only this or that part of it: all the epistles of the apostle speak continually of the grace of Christ. And, lest a single announcement of this grace might seem a little thing, Peter says: “Grace unto you and peace be multiplied.” The Scripture promises abundance; yet we affirm scarcity.
Source: Letters (New Advent)