The Five Books Against Marcion by Tertullian
Chapter V.--Marcion's Cavils Considered. His Objection Refuted, i.e., Man's Fall Showed Failure in God. The Perfection of Man's Being Lay in His Liberty, Which God Purposely Bestowed on Him. The Fall Imputable to Man's Own Choice.
Now then, ye dogs, whom the apostle puts outside, and who yelp at the God of truth, let us come to your various questions. These are the bones of contention, which you are perpetually gnawing! If God is good, and prescient of the future, and able to avert evil, why did He permit man, the very image and likeness of Himself, and, by the origin of his soul, His own substance too, to be deceived by the devil, and fall from obedience of the law into death? For if He had been good, and so unwilling that such a catastrophe should happen, and prescient, so as not to be ignorant of what was to come to pass, and powerful enough to hinder its occurrence, that issue would never have come about, which should be impossible under these three conditions of the divine greatness. Since, however, it has occurred, the contrary proposition is most certainly true, that God must be deemed neither good, nor prescient, nor powerful. For as no such issue could have happened had God been such as He is reputed -- good, and prescient, and mighty -- so has this issue actually happened, because He is not such a God. In reply, we must first vindicate those attributes in the Creator which are called in question -- namely, His goodness and foreknowledge, and power. But I shall not linger long over this point for Christ's own definition comes to our aid at once. From works must proofs be obtained. The Creator's works testify at once to His goodness, since they are good, as we have shown, and to His power, since they are mighty, and spring indeed out of nothing. And even if they were made out of some (previous) matter, as some will have it, they are even thus out of nothing, because they were not what they are. In short, both they are great because they are good; and God is likewise mighty, because all things are His own, whence He is almighty. But what shall I say of His prescience, which has for its witnesses as many prophets as it inspired? After all, what title to prescience do we look for in the Author of the universe, since it was by this very attribute that He foreknew all things when He appointed them their places, and appointed them their places when He foreknew them? There is sin itself. If He had not foreknown this, He would not have proclaimed a caution against it under the penalty of death. Now if there were in God such attributes as must have rendered it both impossible and improper for any evil to have happened to man, and yet evil did occur, let us consider man's condition also -- whether it were not, in fact, rather the cause why that came to pass which could not have happened through God. I find, then, that man was by God constituted free, master of his own will and power; indicating the presence of God's image and likeness in him by nothing so well as by this constitution of his nature. For it was not by his face, and by the lineaments of his body, though they were so varied in his human nature, that he expressed his likeness to the form of God; but he showed his stamp in that essence which he derived from God Himself (that is, the spiritual, which answered to the form of God), and in the freedom and power of his will. This his state was confirmed even by the very law which God then imposed upon him. For a law would not be imposed upon one who had it not in his power to render that obedience which is due to law; nor again, would the penalty of death be threatened against sin, if a contempt of the law were impossible to man in the liberty of his will. So in the Creator's subsequent laws also you will find, when He sets before man good and evil, life and death, that the entire course of discipline is arranged in precepts by God's calling men from sin, and threatening and exhorting them; and this on no other ground than that man is free, with a will either for obedience or resistance.