Ancient times and church
Pagels reminds her reader that in ancient times, Christianity was so radically different in terms of what it looks like to be a Christian. She argues from history, showing that what we consider standard Church Tradition was actually established in real time. Back then, there was no "Tradition," and the very establishment of Tradition meant the mistreatment and elimination of entire Christian communities that were academically viable.
Orthodoxy and heresy
Instead of taking orthodoxy as an automatic assumption, taken for granted, Pagels tries to define these terms more historically. The development of orthodoxy was intentional; it was an attempt to remove competing versions of Christianity from the public. This was clearly about power. What is the imagery of a heretic? By labeling someone as a heretic, their opinion is perfectly invalidated; it is church shame as a weapon against unique or diverse beliefs. Orthodoxy is the development of cult homogeneity.
Jesus the esoteric teacher
The idea of Gnosticism is that Jesus can be seen in a lot of different ways, and only through patient learning and rigorous honesty within one's self can one begin to see the true meanings of Jesus's teaching. The Bible is clear about Jesus's esoteric tendencies, because he taught in riddles, literally. But, in Christian orthodoxy, Jesus is shown as a revealer, never a concealer, so the imagery of Christianity as a mystic pursuit of union with God has been eliminated from the mainstream.
The Church business
The Church is depicted as a business that makes money by donations from patrons. The early church can be seen as a marketplace for competing views about Jesus and the Bible, and so the establishment of canon and orthodoxy can be seen as a conglomeration, and the elimination of rival versions of Christianity can be seen as monopolization. The Catholic tradition successfully monopolized the Christian market and were rewarded with thousands of years of automatic acceptance and approval.
