One God, Old and New Testaments
Tertullian, Against Marcion 19
The Marcionites shoot back: 'Our God, even if not from the beginning, even if not by arrangement, still revealed Himself in Christ Jesus — by His own initiative?' Fine. A book on Christ covering every phase of His career will come later — we must separate the topics so each gets fuller, more orderly treatment — but for now a few words will suffice to show that Christ fulfilled the laws not of some other God but of the Creator.
In the fifteenth year of Tiberius, Christ Jesus deigned to descend from heaven. As for the saving Spirit of Marcion — who willed it so — I never bothered to investigate in which year of Antoninus the Greater he exhaled his dog-star breath from Pontus, though the fact itself is agreed. The Antoninian heretic is impious under Pius. From Tiberius to Antoninus runs about one hundred fifteen and a half years plus half a month. They put the same span between Christ and Marcion. So when Marcion first introduced this God under Antoninus, as we have proven, the case is clear to anyone with sense: the timeline condemns what first appeared under Antoninus as never having appeared under Tiberius — which means the God of the Antoninian empire was not the God of the Tiberian, and therefore was not revealed by Christ, whom all agree Marcion first preached.
I will now prove this consensus from the adversaries themselves. The separation of Law and Gospel is Marcion's proper and principal work, and his disciples cannot deny what they possess in their supreme instrument, by which they are initiated and hardened into this heresy. These are Marcion's 'Antitheses' — opposing contradictions — which try to force a breach between Gospel and Law, so that from the diversity of pronouncements in each instrument they can argue a diversity of gods. Since that very separation of Law and Gospel is what insinuated another God of the Gospel against the God of the Law, it follows that before this separation that God was not in knowledge — He was made known only by the argument of separation — and thus was not revealed by Christ, who preceded the separation, but was invented by Marcion, who established the separation against the peace of Gospel and Law, a peace that reason itself preserved unharmed and unshaken from Christ's appearance to Marcion's audacity, a peace that acknowledged no other God of both Law and Gospel except the Creator, against whom the separation was launched by the Pontic after so much time.
Latin
'Immo', inquiunt Marcionitae, 'deus noster, etsi non ah initio, etsi non per conditionem, sed per sometipsum reuelatus est in Christo Iesu? dabitur et in Christum liber de omni statu eius — distingui enim materias oportet, quo plenius et ordi natius retractentur —: interim satis erit ad praesentem gradum ita occurrere, ut ostendam Christum legum non alterius dei circumlatorem quam creatoris, et quidem paucis. anno quinto . decimo Tiberii Christus Iesus de caelo manare dignatus est. spiritus salutaris Marcionis. [salutis] qui ita uoluit quoto quidem anno Antonini maioris de Ponto suo exhalauerit aura canicularis, non curaui inuestigare. de quo tamen constat. Antoninianus haereticus est, sub Pio impius. a Tiberio autem usque ad Antoninum anni fere centum quindecim et dimidium anni cum dimidio mensis. tantundem temporis ponunt inter Christum et Marcionem. cum igitur sub Antonino primus: Marcion hunc deum induxerit, sicut probauimus, statim. qui sapis, plana res est: praeiudicant tempora quod sub Antonino primum processit sub Tiberio non processisse, id est deum Antoniniani imperii Tiberiani non fuisse, atque ita non a Christo reuelatum quem constat a Marcione primo praedicatum. hoc nunc ut probem constare. quod superest ab ipsis aduersariis sumam. separatio legis et euangelii proprium et principale opus est Marcionis, nec poterant negare discipuli eius quod in summo instrumento habent, quo denique initiantur et indurantur in hanc haeresim. nam hae sunt 'Antithesis' Marcionis, id est contrariae oppositiones. quae conantur discordiam euangelii cum lege committere. ut ex diuersitate sententiarum utriusque instrumenti diuersitatem quoque argumententur deorum. igitur cum ea separatio legis et euangelii ipsa sit, quae alium deum euangelii insinuauerit aduersus deum legis, apparet ante eam separationem deum in notitia non fuisse, qui ab argumento separationis innotuit, atque ita non a Christo reuelatum qui fuit ante separationem, sed a Marcione commentatum, qui instituit separationem aduersus euangelii legisque pacem, quam retro inlaesam et inconcussam ab apparentia Christi usque ad audaciam Marcionis illa utique ratio seruauit, quae non alium deum et legis et euangelii tuebatur praeter creatorem, aduersus quem tanto post tempore separatio a Pontico inmissa est.