Finally, how was Marcion of Sinope defeated doctrinally?
I would answer this last question first.
Marcion was a dualist: he believed that the God of the Old Testament - the
Demiurge that created the material world according to him - was an inferior, somewhat vengeful and jealous tribal
Jewish deity, whose law represents legalistic reciprocal justice and who punishes mankind for its sins through suffering and death. Contrastingly, the God that Jesus professed is an altogether different and more superior being, a universal God of compassion and love who looks upon humanity with benevolence and mercy.
Because Marcion believed that the world was created by the Demiurge, he held it to be evil (in this he was in alignment with gnostic thought). Hence, he was also a
Docetist: he was of the idea that Jesus never really became a flesh-and-blood human but just
appeared to have a material body. Unlike gnostic sects however, who generally believed that every human being is born with a small piece of the ‘divine spark’ lodged within his/her spirit, Marcion held the idea that the Heavenly Father was an utterly alien God; he had no part in making the physical world, nor any connection with it. He really only agreed to help mankind out of His mercy.
Marcion proposed a Scriptual canon of his own, which consisted of only eleven books grouped into two sections: the
Evangelikon, a sort of truncated version of the Gospel of Luke, and the
Apostolikon, a selection of ten letters by St. Paul, who Marcion considered the correct interpreter and transmitter of Jesus’ teachings. Both sections were purged of elements relating to Jesus’ birth and childhood, Judaism (Marcion was pretty much anti-Jewish, as you can see), and material which challenged his beliefs.
Take for example Jesus’ prayer: “
I give you thanks, Father, Lord of heaven and earth” is changed to “
I give thanks, Father, Lord of heaven” (since God never had any affinity with the earth, Marcion cut it off); “
O foolish and hard of heart to believe in all that the prophets have spoken,” is changed into, “
O foolish and hard of heart to believe in all that I have told you” (because the prophets were acting under the orders of the OT God); the accusation that the chief priests lay against Jesus, “
We found this one subverting our nation” (receives the addition: “
and destroying the law and the prophets” (which makes Jesus anti-Jewish like Marcion!)
Some orthodox writers have taken on Marcion, one of them being Tertullian: he makes reference to Marcion in several of his works, such as
De Carne Christi (On the Flesh of Christ),
De Resurrectione Carnis (On the Resurrection of the Flesh),
De Anima (On the Soul) and devotes a five-book work specifically targeted against Marcion:
Adversus Marcionem (Against Marcion). Aside from him, St. Justin Martyr also makes a reference to the Marcionites in his
First Apology and St. Irenaeus refers to Marcion, however, again and again in his
Against Heresies (especially in Books 3 and 4). Rather than repeat it all here, I’d rather you read them for yourself.
