Marcion had perfectly valid points, of course; Jesus has nothing to do with the prophecies in the Tanakh about the warrior-Saviour who will crush the enemies of the Judeans and give them loads of land and such
Hence why he argued that the Father of IS must be a different God, and it's a perfectly valid argument - which would destroy every "legal" base to Paul, Mark, and so on: take away the Tanakh and Jesus becomes just some awkward idiot allegedly doing miracles (which are impossible to verify and validate) and ending up with a stake up his ass - not a firm basis for a religion
Doesn't anyone see that all of it is mere politics?
The only goal that the church fathers have is to save their nascent religion - if that takes a few lies here and there then what's there to it really, it's all for the greater good: economic and political stability, general well-being of the public now that the Jewish Law has become abolished, and so on.
Judaism was great to exert power and control over the masses, it kept them checked - but after Bar Kokhba, all of it was gone and that must have been noticeable
There must have been a reason for the sudden endorsement of the crazy idea of "Jesus saves" in general.
I'm starting to think that all of it was done and dusted in a matter of a few decades, with Paul stealing Marcion in 140, Mark backing up that story in 145, and Justin following up with more Marcion (Luke) and writing Matthew himself in 150. Then the two pieces / different worlds needed to be glued together, and he did another one and it was called Acts
Think of it: a religion controlled by Romans - not only could they keep the public in check for free, but they would even make money off of it! They could never have dreamed how much that would be, really.
And like today, it was decided to set up a separate private company for it
Oh, regarding the anti Judean stuff:
c 8 BYZ and TR include βαπτισμοὺς ξεστῶν καὶ ποτηρίων· καὶ ἄλλα παρόμοια τοιαῦτα πολλὰ ποιεῖτε
So Mark 7 only says the following:
8 Ἀφέντες τὴν ἐντολὴν τοῦ Θεοῦ κρατεῖτε τὴν παράδοσιν τῶν ἀνθρώπων.”c
"Having-dismissed the direction of God, you-made-strong the tradition of humans"