One of the most fascinating features of early Christianity is that so many different Christian groups were saying so many contrary things. It is not just that they said different things. They often said just the opposite things. There is only one God. No, there are many gods. The material world is the good creation of a good God. No, it comes from a cosmic disaster in the divine realm. Jesus came in the flesh. No, he was totally removed from the flesh. Eternal life comes through the redemption of the flesh. No it comes through escaping the flesh. Paul taught these things. No, Paul taught those other things. Paul was a true apostle. No, Paul misunderstood the message of Jesus. Peter and Paul agreed on every theological point. No, they were completely at odds with one another. Peter taught that Christians were not to follow the Jewish law. No, he taught that the Jewish law continued to be in force. And on and on and on, world without end.
Not only did those on every side in all of these debates think that they were right and that their opponents were wrong; they also maintained in all sincerity and honesty that their views were the ones taught by Jesus and his apostles. What is more, they all, apparently produced books to prove it, books that claimed to be written by apostles and supported their own points of view. What is perhaps more interesting of all, the vast majority of these apostolic books were in fact forged. Christians intent on establishing what was right to believe did so by telling lies, in an attempt to deceive their readers into agreeing that they were the ones who spoke the truth.
This from Bart Ehrman's newest book, Forged: Writing in the Name of God--Why the Bible's Authors Are Not Who We Think They Are.