Elenchus 6. If he has mentioned prophets he does not deny prophets. If he avenges the murder of the prophets and blames their murderers and persecutors, he is not foreign to prophets. Rather, he is their god, who establishes their authenticity.
Tertullian Against Marcion 4:15
In like manner, he says, did their fathers to the prophets. See this turncoat Christ, first the destroyer of the prophets, and next the vindicator of them: as their enemy destroying them, by converting their disciples to himself: as a friend, vindicating them, by casting reproach upon their persecutors. Now, in so far as vindication of the prophets would have been out of character with the Christ of Marcion who had come to destroy them, to that same extent it is in character with the Creator's Christ to cast reproach upon the persecutors of those prophets whom in all points he was fulfilling—at least because to blame the sons for the fathers' sins is more in keeping with the Creator than it is with that god who does not even censure a man for his own sins. But, you say, he was not necessarily acting in defence of the prophets if it was his intention to insist on the iniquity of the Jews in not treating with kindness even their own prophets. Yes, but here there was no excuse for blaming the Jews for wrongdoing: they should rather have been praised and commended, if they took strong action against those to whose destruction after all these ages your very good god has at last bestirred himself.
This is perhaps the most important section we have come across so far as it clearly betrays a critical part of Epiphanius's methodology. Tertullian quotes the section as 'did their fathers unto the prophets' while Epiphanius has it 'your fathers unto the prophets.' Many people have simply assumed that Epiphanius is reporting a Marcionite variant from his 'expert' examination of the original Marcionite gospel. Yet Sense points out that the reading actually is only found in Epiphanius's own gospel. In other words, Epiphanius is citing here not from Marcion's gospel, nor from Irenaeus (or his source) but his own text as we see it reappear in other sections of his writing. For instance the section against Mani - καὶ «Ἀβραὰμ ὁ πατὴρ ὑμῶν ἠγαλλιάσατο ἰδεῖν τὴν ἡμέραν μου, καὶ εἶδε καὶ ἐχάρη,» καὶ «οὕτως οἱ πατέρες ὑμῶν ἐποίουν τοῖς προφήταις,» καὶ «μακάριοί ἐστε, ὅταν ὀνειδίσωσιν ὑμᾶς καὶ εἴπωσι καθ' ὑμῶν πᾶν πονηρὸν ψευδόμενοι. χαίρετε καὶ ἀγαλλιᾶσθε, ὅτι ὁ μισθὸς ὑμῶν πολὺς ἐν τοῖς οὐρανοῖς· οὕτω γὰρ ἐδίωκον τοὺς προφήτας τοὺς πρὸ ὑμῶν»
Clearly then Epiphanius decision to omit Irenaeus's long section dealing with the 'Sermon on the Mount' is connected with his sudden 'switch' to his own text. There are parts of the 'study' where Epiphanius decides to 'switch' to his own text and replace what he saw as an unnecessary and ultimately ineffective original argument with a quick one of his own making. In this case "If he has mentioned prophets he does not deny prophets. If he avenges the murder of the prophets and blames their murderers and persecutors, he is not foreign to prophets. Rather, he is their god, who establishes their authenticity." The argument originally came from Irenaeus (= Tertullian). It was the only one which Epiphanius considered worthy enough to keep. But it also shows that Epiphanius (a) is not using the Marcionite gospel and (b) his citations - even when they seem to represent variants - are often times just reflective of his own text.
dating back to conversations with his grandfather, Gaston Frank. "He said we represent one of the last descendants of the Frankist Jewish faith in the world," he muses. "I grew up thinking that our family was something like the Last of the Mohicans."