Against Marcion: Book II 24Instances of God's Repentance, and Notably in the Case of the Ninevites, Accounted for and Vindicated.

Furthermore, with respect to the repentance which occurs in His conduct, you interpret it with similar perverseness just as if it were with fickleness and improvidence that He repented, or on the recollection of some wrong-doing; because He actually said, "It repenteth me that I have set up Saul to be king," very much as if He meant that His repentance savoured of an acknowledgment of some evil work or error. Well, this is not always implied. For there occurs even in good works a confession of repentance, as a reproach and condemnation of the man who has proved himself unthankful for a benefit. For instance, in this case of Saul, the Creator, who had made no mistake in selecting him for the kingdom, and endowing him with His Holy Spirit, makes a statement respecting the goodliness of his person, how that He had most fitly chosen him as being at that moment the choicest man, so that (as He says) there was not his fellow among the children of Israel. Neither was He ignorant how he would afterwards turn out. For no one would bear you out in imputing lack of foresight to that God whom, since you do not deny Him to be divine, you allow to be also foreseeing; for this proper attribute of divinity exists in Him. However, He did, as I have said, burden the guilt of Saul with the confession of His own repentance; but as there is an absence of all error and wrong in His choice of Saul, it follows that this repentance is to be understood as upbraiding another rather than as self-incriminating. Look here then, say you: I discover a self-incriminating case in the matter of the Ninevites, when the book of Jonah declares, "And God repented of the evil that He had said that He would do unto them; and He did it not." In accordance with which Jonah himself says unto the Lord, "Therefore I fled before unto Tarshish; for I knew that Thou art a gracious God and merciful, slow to anger, and of great kindness, and repentest Thee of the evil." It is well, therefore, that he premised the attribute of the most good God as most patient over the wicked, and most abundant in mercy and kindness over such as acknowledged and bewailed their sins, as the Ninevites were then doing. For if He who has this attribute is the Most Good, you will have first to relinquish that position of yours, that the very contact with evil is incompatible with such a Being, that is, with the most good God. And because Marcion, too, maintains that a good tree ought not to produce bad fruit; but yet he has mentioned "evil" (in the passage under discussion), which the most good God is incapable of, is there forthcoming any explanation of these "evils," which may render them compatible with even the most Good? There is. We say, in short, that evil in the present case means, not what may be attributed to the Creator's nature as an evil being, but what may be attributed to His power as a judge. In accordance with which He declared, "I create evil," and, "I frame evil against you;" meaning not to sinful evils, but avenging ones. What sort of stigma pertains to these, congruous as they are with God's judicial character, we have sufficiently explained. Now although these are called "evils," they are yet not reprehensible in a judge; nor because of this their name do they show that the judge is evil: so in like manner will this particular evil be understood to be one of this class of judiciary evils, and along with them to be compatible with (God as) a judge. The Greeks also sometimes use the word "evils" for troubles and injuries (not malignant ones), as in this passage of yours is also meant. Therefore, if the Creator repented of such evil as this, as showing that the creature deserve decondemnation, and ought to be punished for his sin, then, in the present instance no fault of a criminating nature will be imputed to the Creator, for having deservedly and worthily decreed the destruction of a city so full of iniquity. What therefore He had justly decreed, having no evil purpose in His decree, He decreed from the principle of justice, not from malevolence. Yet He gave it the name of "evil," because of the evil and desert involved in the very suffering itself. Then, you will say, if you excuse the evil under name of justice, on the ground that He had justly determined destruction against the people of Nineveh, He must even on this argument be blameworthy, for having repented of an act of justice, which surely should not be repented of. Certainly not, my reply is; God will never repent of an act of justice. And it now remains that we should understand what God's repentance means. For although man repents most frequently on the recollection of a sin, and occasionally even from the unpleasantness of some good action, this is never the case with God. For, inasmuch as God neither commits sin nor condemns a good action, in so far is there no room in Him for repentance of either a good or an evil deed. Now this point is determined for you even in the scripture which we have quoted. Samuel says to Saul, "The Lord hath rent the kingdom of Israel from thee this day, and hath given it to a neighbour of thine that is better than thou;" and into two parts shall Israel be divided: "for He will not turn Himself, nor repent; for He does not repent as a man does." According, therefore, to this definition, the divine repentance takes in all cases a different form from that of man, in that it is never regarded as the result of improvidence or of fickleness, or of any condemnation of a good or an evil work. What, then, will be the mode of God's repentance? It is already quite clear, if you avoid referring it to human conditions. For it will have no other meaning than a simple change of a prior purpose; and this is admissible without any blame even in a man, much more in God, whose every purpose is faultless. Now in Greek the word for repentance (metanoia) is formed, not from the confession of a sin, but from a change of mind, which in God we have shown to be regulated by the occurrence of varying circumstances.