On Saint Athanasius (two books) 2.32–2.34

Hear also what your dearest friend did to Adam and Eve, and you will find that you are now doing to us what he did then to them. “And they were both naked,” says Moses in Genesis, “Adam and his wife, and they were not ashamed. Now the serpent was wiser than all the beasts there were”; and further on: “And the serpent said to the woman: Why is it that the Lord God said that you shall not eat of every tree that is in paradise? And the woman said to the serpent: Of every tree that is in paradise we will eat; but of the fruit of the tree which is in the midst of paradise, God said, you shall not eat of it, nor even touch it, lest you die.” We say to you, who in the serpent's place persuade us to condemn an unheard man and slaughter an innocent one: The Lord has commanded that the innocent and righteous are not to be killed. “And the serpent said to the woman: You will not die. For God knew that on whatever day you eat of it, your eyes will be opened, and you will be like gods, knowing good and evil.” And as this serpent says to us through you, “You will be more righteous if you shed righteous blood; you will be more blessed if you anathematize the apostolic and evangelical faith and accept the Arian faithlessness” … his deceit is trampled underfoot, by God's favour, by us in you, since we know it already. But God is witness that we grieve for you, because the serpent has set himself through you to ensnare us; for it is clear that then he assailed Adam and Eve by himself. I beg you not to take hard what is put forward for the sake of your salvation. For I suppose you are grieved that I have said the serpent assailed us through you and that in many places I have put you among those who have been called serpents. Consider your work and theirs, and if you do not recognize that you are one body, say that I speak unjustly. You hear that your teachers in faithlessness, the Jews, are often called serpents by the Lord in the holy Gospels: “Serpents, brood of vipers.” Why did they deserve to be called by this name? Surely because of their wicked work, surely because of their unbelief. Hence too John the Baptist says to them: “Brood of vipers, who showed you to flee from the wrath to come? Bear, then, fruits worthy of repentance.” As, then, some of them, who believed in the only Son of God and corrected their ways, deserved to become sons of light, while others are called serpents, so you too, unless you bear fruits worthy of repentance, unless you correct your ways, will be called a son of the viper and of the serpent. For which of the servants of God, seeing you to be a murderer and a blasphemer, would not call you by the name by which the Jews are called? Who among those who fear God will hesitate to declare what you are, when he sees that the scribes, Pharisees and rulers of the Jews are called serpents because they both shed the blood of the prophets and denied the only Son of God?

Since this is so, it remains for you to repent of your deeds, observing that God has shown the mercy of his clemency to all who turn from evil ways, and having the example of the Ninevites; if you imitate them, you must obtain the help of mercy as they did. Hear what was done in their regard, and what they themselves did, terrified by the preaching of Jonah. “The whale was commanded,” says holy Scripture, “and it cast Jonah out upon the land. And the word of the Lord came to Jonah a second time, saying: Arise, go to Nineveh, the great city, and preach in it according to the former preaching which I spoke to you. And Jonah arose and went to Nineveh, according to what the Lord had spoken to him. Now Nineveh was a great city, a journey of about three days. And Jonah began to go into the city about a day's journey, and he preached and said: Three days more, and Nineveh will be overthrown. And the men of Nineveh believed God and proclaimed a fast and clothed themselves in sackcloth from the greatest to the least of them. And the word reached the king of Nineveh, and he rose from his throne and took off his robe and put sackcloth around himself and sat on ashes. And it was proclaimed by the king of Nineveh and by his magistrates, saying: Let men and beasts and oxen and sheep taste nothing, nor feed, nor drink water. And the men put sackcloth around themselves, and men and beasts cried out to God earnestly, and each turned from his evil way and from the iniquity of his hands, saying: Who knows whether God will repent and turn from the anger of his fury, and we shall not perish? And God saw their work, that each had turned from his evil way; and God repented of the evil which he had said he would do to them, and he did not do it. And Jonah was grieved with a great grief and was confounded, and he prayed to God, saying: O Lord, are these not my words, when I was still in my land? That is why I hastened to flee to Tarshish, for I knew that you are compassionate and kind, patient and merciful, and repenting of evils”; and further on: “And God said to Jonah: Are you very grieved over the gourd? I am very grieved, even to death. And the Lord said: You have spared the gourd, for which you did not labour nor make it grow, which came up in a night and perished in a night; and shall I not spare Nineveh, the great city, in which live more than a hundred and twenty thousand people who do not know their right hand from their left?” And if God sees that you have cast off your wicked work, Constantius, if he sees your ruined ways corrected and you reformed in everything, believe me, you will begin to be in great happiness among the servants of God.

You have besides the example of the most blessed apostle Paul, in case you, like him, do these things in ignorance: that as soon as you turn to confess the only Son of God, he will grant you pardon for your crimes as he did him. Follow him, take hold of his way, hear him speaking to the Philippians, both what he was before he knew Christ and how great a blessedness he deserved to obtain after he knew him: “If anyone thinks he has confidence in the flesh, I more: circumcised on the eighth day, of the race of Israel, of the tribe of Benjamin, a Hebrew of Hebrews; as to the law a Pharisee; as to zeal a persecutor of the church; as to the righteousness which is in the law, living without blame. Whatever gains I had, these I counted loss for Christ's sake. Indeed I count all things loss because of the surpassing worth of the knowledge of Christ Jesus our Lord, for whose sake I have suffered the loss of all things and count them dung, that I may gain Christ and be found in him, not having my own righteousness, which is from the law, but that which is through faith in Jesus Christ, the righteousness from God in faith, that I may know him and the power of his resurrection and the sharing of his sufferings, being conformed to his death, if somehow I may attain to his resurrection from the dead.” As has already been said, imitate him, follow him, so that, since he too was what you are now, a persecutor of the church, a denier of the only Son of God, you may be found to have been converted in the same way to obtain the heavenly kingdoms, from faithlessness to accepting the catholic faith, so that you too may pass from death to life. For hear further that he persecuted the church out of ignorance of God, as he himself reveals to Timothy: “But we know that the law is good, if one uses it lawfully, knowing this, that the law is not laid down for the righteous, but for the unjust and disobedient, for the ungodly and sinners, for the wicked and profane, for parricides and matricides, for murderers, the indecent, men who lie with males, kidnappers, liars, perjurers, and whatever else is contrary to sound teaching, according to the gospel of the glory of the blessed God which was entrusted to me. And I give thanks to him who strengthened me, Christ Jesus our Lord, because he judged me faithful, appointing me to his ministry, though I was formerly a blasphemer and a persecutor and insolent; but I obtained mercy, because I acted ignorantly in unbelief. And the grace of our Lord overflowed with the faith and love that are in Christ Jesus.” So you too, from a persecutor, an insolent man and a blasphemer, can become blessed and truly most dear to God, if, like the blessed Paul, you believe that Jesus Christ is the true Son of God; if you confess that he has always reigned and will reign with the Father, that is, without beginning and without end; if you do not resist the sacred Scriptures, which cry out that the Father and the Son and the Holy Spirit have one eternity; if, in short, you believe that the Father and the Son and the Holy Spirit have one Godhead. Believe me, you will be in the choir of the patriarchs, prophets, apostles and martyrs; otherwise you will blame yourself, when you begin to see yourself tormented with the devil and all his henchmen, for having despised these so healthful admonitions of ours.