Ante-Nicene Fathers, Vol III:
Tertullian: Part II: In the Attribute of Justice, Marcion's God is Hopelessly Weak and Ungodlike. He Dislikes Evil, But Does Not Punish Its Perpetration.

Chapter XXVI.—In the Attribute of Justice, Marcion’s God is Hopelessly Weak and Ungodlike.  He Dislikes Evil, But Does Not Punish Its Perpetration.

But it is here sufficient that the extreme perversity of their god is proved from the mere exposition of his lonely goodness, in which they refuse to ascribe to him such emotions of mind as they censure in the Creator.  Now, if he is susceptible of no feeling of rivalry, or anger, or damage, or injury, as one who refrains from exercising judicial power, I cannot tell how any system of discipline—and that, too, a plenary one—can be consistent in him. For how is it possible that he should issue commands, if he does not mean to execute them; or forbid sins, if he intends not to punish them, but rather to decline the functions of the judge, as being a stranger to all notions of severity and judicial chastisement? For why does he forbid the commission of that which he punishes not when perpetrated? It would have been far more right, if he had not forbidden what he meant not to punish, than that he should punish what he had not forbidden. Nay, it was his duty even to have permitted what he was about to prohibit in so unreasonable a way, as to annex no penalty to the offence. 2657 For even now that is tacitly permitted which is forbidden without any infliction of vengeance. Besides, he only forbids the commission of that which he does not like to have done.  Most listless, therefore, is he, since he takes no offence at the doing of what he dislikes to be done, although disp. 292 pleasure ought to be the companion of his violated will. Now, if he is offended, he ought to be angry; if angry, he ought to inflict punishment. For such infliction is the just fruit of anger, and anger is the debt of displeasure, and displeasure (as I have said) is the companion of a violated will. However, he inflicts no punishment; therefore he takes no offence.

He takes no offence, therefore his will is not wronged, although that is done which he was unwilling to have done; and the transgression is now committed with the acquiescence of 2658 his will, because whatever offends not the will is not committed against the will. Now, if this is to be the principle of the divine virtue or goodness, to be unwilling indeed that a thing be done and to prohibit it, and yet not be moved by its commission, we then allege that he has been moved already when he declared his unwillingness; and that it is vain for him not to be moved by the accomplishment of a thing after being moved at the possibility thereof, when he willed it not to be done. For he prohibited it by his not willing it. Did he not therefore do a judicial act, when he declared his unwillingness, and consequent prohibition of it? For he judged that it ought not to be done, and he deliberately declared 2659 that it should be forbidden.  Consequently by this time even he performs the part of a judge. If it is unbecoming for God to discharge a judicial function, or at least only so far becoming that He may merely declare His unwillingness, and pronounce His prohibition, then He may not even punish for an offence when it is committed.  Now, nothing is so unworthy of the Divine Being as not to execute retribution on what He has disliked and forbidden. First, He owes the infliction of chastisement to whatever sentence or law He promulges, for the vindication of His authority and the maintenance of submission to it; secondly, because hostile opposition is inevitable to what He has disliked to be done, and by that dislike forbidden. Moreover, it would be a more unworthy course for God to spare the evil-doer than to punish him, especially in the most good and holy God, who is not otherwise fully good than as the enemy of evil, and that to such a degree as to display His love of good by the hatred of evil, and to fulfil His defence of the former by the extirpation of the latter.

Footnotes

Ut non defensurus. Defendo = vindico. See Oehler’s note for other instances.

Secundum.

Pronunciavit.