According to traditions recorded in the gospels, Jesus commissioned his apostles to spread the gospel to all nations. Christianity expanded and by the 2nd century, the majority of Christians were descendants of converts who had no Jewish background. Within the diverse movement, some communities like the Gnostics questioned the relevance of the Jewish inheritance, while others like the Ebionites continued to insist on observing the Law of Moses. In the year 139, a wealthy ship-owner named Marcion arrived in the city of Rome and made a substantial donation to the church there. Over the next several years Marcion promoted his belief among the Christians in Rome that the God of the Hebrew Bible is incompatible with the teachings of Jesus. Like the Gnostics, Marcion concluded that the texts mistook an inferior craftsman deity (or Demiurge) for the true spiritual God (the Monad), and that Jesus was not the Jewish messiah, but a spiritual Savior. (However, in contrast to the Gnostics, Marcion did not promote an elaborate new cosmogeny of divine emanations and entities.) Marcion drew up a list of books that he believed should be canonical — the first Christian to propose a New Testament canon. This consisted of a single gospel that resembled Luke (but differed in some respects), along with a collection of Paul’s letters. The other gospels were excluded, and the entire Old Testament was to be discarded. By 144, leaders of the Roman church rejected Marcion’s teachings and excommunicated him. Undeterred, Marcion returned to Anatolia where he established a competing church network that initially thrived and may have continued to exist into the 10th century. John Hamer of Toronto Centre place will look into what we can know about Marcion, his teachings, and his church. And he will consider the effects Marcionism had on orthodox Christianity.