The next heresy in B. Quash and M. Ward, Heresies and How to Avoid Them: Why It Matters What Christians Believe  concerns Marcion and asks this question: Can Christians dispense with the God of the Old Testament?

I hear this one all the time: the so-called “God of the Old Testament” is fierce and wrathful but the God of Jesus is gracious and loving. This heresy is that the God of the Old Testament and the God of Jesus are at odds with one another.

What makes this one so bitterly distasteful is not only the number of its early proponents and defenders, but the incredible offense it brings to the unity of the Bible, to the Israelite roots of the Christian faith, and to the potential damage in anti-Semitism.

Ultimately, as Angela Tilby (author of this chp; Anglican Vicar) argues, Marcion found holiness and love incompatible. Marcion would have nothing to do with the threat of judgment, the warning of hell, the law, and the call to obedience. And the reason why Marcion thought so many Christians believed these things? The Old Testament. Solution: chuck it and its Jewish heritage. The God of the OT was ignorant (Gen 1:9), immoral (2 Sam 5–24), and inconsistent (Exod 20 and Numb 21:8).

But this landed Marcion in trouble with the continuity themes and with texts like Matthew, so he thought Jews had corrupted the grace of Jesus and he — in Thomas Jefferson-like fashion — cut out those parts too. He believed on Luke’s Gospel and some of the letters of Paul.

Tilby does not think Julian of Norwich or Martin Luther were Marcionites, even if some have tried to read them that way. She finds closer parallels in the “later liberal Protestantism” of Germany. Think Adolf von Harnack. She also admits to being tempted to this when she listens to the bullying approaches of some conservative Christians today. She also sees a similar thing in the bullying intolerance of some liberals, and mentions David Jenkins.

Marcion really rejected creation. She finds Marcionistic-like thinking in the Jesus Seminar. A useful test for the presence of Marcionism is anti-Semitism. Instead of searching for contradictions, she advises searching for compatibilities.