Lost Christianities - Bart Ehrman

Christianities: The Battles for Scripture and the Faiths We Never Knew. Ehrman says some groups of early Christians claimed there was more than one God. Some believed Jesus was human but not divine, while others said he was divine but not human. In his book, Ehrman looks at how these early forms of Christianity came to be suppressed, reformed, or forgotten. He spoke recently with Beliefnet about what Christianity might have become if a different strain had emerged victorious from first-century intellectual battles.

Your book discusses the hypothetical questions of what would have happened to Christianity, and by extension world history, if a different type of Christianity had survived. What are your best guesses about that?

It depends on which of the other sides had won. The Marcionites decided that everything Jewish had to be taken out of the New Testament and that the Jewish Bible was no longer going to considered part of the scriptures. They thought there were two different Gods--the God of the Jews and the God of Jesus. If they had won, then I guess we wouldn't have an Old Testament anymore and there would be no connection between Judaism and Christianity. My hunch is that if that had happened, anti-Semitism wouldn't have developed among Christians. What drove anti-Semitism was the competition between the Jewish understanding of scripture and the Christian understanding of scripture. But if there were no competition because they didn't have the same scripture, then we may well have never had any anti-Semitism.
The Ebionites were opponents of the Apostle Paul. They thought he was a heretic. A lot of the New Testament had to do with the Apostle Paul and his writings. Those would have been excluded from the get-go. They would have kept what is now our Gospel of Matthew but maybe not any of the other Gospels. And it would mean that Christians would have to be Jewish