Marcion was born the son of the bishop of Sinope in Pontus, in the Black Sea region, around 85. As a wealthy ship owner, he made large financial donations to the church in Rome. After going to Rome around 135-140, he was excommunicated because of his numerous conflicts with the church elders. After his excommunication, he returned to Sinope around 144 where he began his own brand of Christianity that spread throughout the Roman empire

Marcion taught that the Old and New Testaments cannot be reconciled to each other and that there are two gods—one of the Old Testament and one of the New Testament represented by Jesus Christ. Marcion rejected the Old Testament and accepted the following books of the New Testament: The Gospel of Luke, Galatians, 1 Corinthians, 2 Corinthians, Romans, 1 Thessalonians, 2 Thessalonians, Ephesians (which Marcion called Laodiceans), Colossians, Philemon, and Philippians. In response to Marcion, bishop Athanasius of Alexandria, Egypt (296-373) presented the twenty-seven books that today comprise the New Testament.

Marcion separated himself from the bishops of Asia Minor (modern Turkey), including Polycarp of Smyrna, and Papias and Abercius of Hierapolis. Although Marcion died around 160, the Marconite churches continued in some areas of the Roman empire until around the 900s.