Against the Manichaeans 16–18

Since we have also heard it said by them that the words "Serpents, offspring of vipers", spoken to those born of Abraham and of the other holy men, show that those around Abraham are vipers, let them know that what they say conflicts with the sequence of the passage. For he rebukes them as not being of Abraham but offspring of vipers, who pretend and vainly boast that they are of Abraham. For in another passage the Savior says to them: "This Abraham did not do" (Abraham, whom you falsely say is your father). "For if you were children of Abraham, you would do the works of Abraham. But you are of your father the devil, and you want to do the desires of your father. He was a murderer from the beginning, and has not stood in the truth." And well is it said, "has not stood", showing that he formerly stood in the truth. He calls the devil their father because of the likeness of their turning and their quality. So he did not call Abraham and the holy men with him vipers. For they came to be sons of vipers by change, because they used evil teachers, as has been said, by their own choice. John, then, says to them: Since by a change away from virtue you chose to become serpents (for they were not such in substance), stop being offspring of vipers, whose quality you chose to have. For you made it your aim to be evil sons of evil men and unjust sons of the unjust. But since by coming to baptism you claim to bear a sign of repentance, but do this in pretense, I say to you: "Who warned you to flee from the coming wrath?" For the one who repents repents for this reason, that by sinning no more he may flee the coming wrath … the words "Who warned you?", meaning: the one who genuinely warns men to withdraw from wickedness does not have it done in pretense. But you do this with hypocrisy when you come to be baptized. You will not, then, be cleansed. For the one who truly wishes to be cleansed departs from sins and bears the fruit of such repentance, doing the works of the habit contrary to sin. But this you have not done, and you have condemned yourselves by saying that you have Abraham as father. But what will profit you is not thinking that you are children of Abraham, but being his children, both by faith and by fleeing from idols. So even if you once were children of Abraham, this will not save you. For also those who are not now … he is saved who is a child of Abraham by virtue, not one who became his child according to the flesh only; and even if he becomes one, let him not be proud, for such a thing can be lost. And certainly those who do not have it will be able to acquire it. For Paul too says to those whom he did not beget in the flesh: "For in Christ through the gospel I begot you."

But when you hear these things, do not despise them, as though the wrath against sinners were slow. For already, through his very sinning, the base man has punishment present with him, since he is liable to punishment. Therefore know the … he means not perceptible trees but men made such by wickedness. The root of these trees is the worst habit, from which comes fruit that is not edible but poisonous. That, then, he called fruit that is not good. So even if the axe signifies punishment, and the bad tree the man who sins, these are not conflicting natures; for punishment is threatened so that the trees may change. For the one who threatens sinners wishes by the threat itself to transform them. If, then, by the threat of the axe that is going to cut down the rotten trees he persuades them to stop bearing bad fruit and to bear good fruit, the tree is not evil by nature, nor is punishment evil by nature …

But perhaps they will say: If punishment transforms the base, it is good; and if punishment is good, and the promise is its contrary, and contraries cannot both be good at the same time, then the promise is evil. But since the promise is not evil but good, punishment is evil. And if punishment is evil, it is not God but Satan who brings it. But Satan does not bring punishment on his own, for they are evil like him, and he too would of necessity fall under punishment; so he would bring it on the good. But this is impossible; therefore it is not the evil one who brings it, but God. And everything that God brings, usefully …