The Five Books Against Marcion by Tertullian
Chapter IV.--Marcion's Christ Not the Subject of Prophecy The Absurd Consequences of This Theory of the Heretic.
He disdained, I suppose, to imitate the order of our God, as one who was displeasing to him, and was by all means to be vanquished. He wished to come, as a new being in a new way -- a son previous to his father's announcement, a sent one before the authority of the sender; so that he might in person propagate a most monstrous faith, whereby it should come to be believed that Christ was come before it should be known that He had an existence. It is here convenient to me to treat that other point: Why he came not after Christ? For when I observe that, during so long a period, his lord bore with the greatest patience the very ruthless Creator who was all the while announcing His Christ to men, I say, that whatever reason impelled him to do so, postponing thereby his own revelation and interposition, the self-same reason imposed on him the duty of bearing with the Creator (who had also in His Christ dispensations of His own to carry out); so that, after the completion and accomplishment of the entire plan of the rival God and the rival Christ, he might then superinduce his own proper dispensation. But he grew weary of so long an endurance, and so failed to wait till the end of the Creator's course. It was of no use, his enduring that his Christ should be predicted, when he refused to permit him to be manifested. Either it was without just cause that he interrupted the full course of his rival's time, or without just cause did he so long refrain from interrupting it. What held him back at first? Or what disturbed him at last? As the case now stands, however, he has committed himself in respect of both, having revealed himself so tardily after the Creator, so hurriedly before His Christ; whereas he ought long ago to have encountered the one with a confutation, the other to have forborne encountering as yet -- not to have borne with the one so long in His ruthless hostility, nor to have disquieted the other, who was as yet quiescent! In the case of both, while depriving them of their title to be considered the most good God, he showed himself at least capricious and uncertain; lukewarm (in his resentment) towards the Creator, but fervid against His Christ, and powerless in respect of them both! For he no more restrained the Creator than he resisted His Christ. The Creator still remains such as He really is. His Christ also will come, just as it is written of Him. Why did he come after the Creator, since he was unable to correct Him by punishment? Why did he reveal himself before Christ, whom he could not hinder from appearing? If, on the contrary, he did chastise the Creator, he revealed himself, (I suppose,) after Him in order that things which require correction might come first. On which account also, (of course,) he ought to have waited for Christ to appear first, whom he was going to chastise in like manner; then he would be His punisher coming after Him, just as he had been in the case of the Creator. There is another consideration: since he will at his second advent come after Him, that as he at His first coming took hostile proceedings against the Creator, destroying the law and the prophets, which were His, so he may, to be sure, at his second coming proceed in opposition to Christ, upsetting His kingdom. Then, no doubt, he would terminate his course, and then (if ever) be worthy of belief; for else, if his work has been already perfected, it would be in vain for him to come, for there would indeed be nothing that he could further accomplish.