Marcion, a native of Sinope in Pontus…

Marcion, a native of Sinope in Pontus and a devoted Christian, had immigrated to Rome around 140 and attached himself to the church there.

Associating in Rome with the Syrian Gnostic, Cerdo, Marcion had developed unorthodox perspectives that soon brought him into conflict with the Roman church.

Arguing that the Christian God of love could not have also been the Creator God of the Old Testament, Marcion had maintained that Judaizing tendencies among the earliest disciples have corrupted the original gospel of Jesus and that the Old Testament holds no validity for Christians.

The only one to have correctly understood the original teachings of Jesus, claims Marcion, was Paul.

Rejecting the gospels of Matthew, Mark, and John, he collects ten of Paul's letters and an edited “Gospel According to Luke,” from which he removes all legalistic and Old Testament references; he claims that these documents constitute the rule or canon of the church's teaching.

The Christian church in Rome, compelled to define what it accepts as the true canon, excommunicates Marcion in about 144 and begins assembling the New Testament canon (the version accepted today, inclusive of all four gospels).

Marcion’s substantial following grows rapidly into a sect, based mainly on the premise that the gospel of Jesus Christ is entirely a gospel of love to the exclusion of the Mosaic Law.