Novatianism

The heresy of Novatianism was an early Christian sect named after its founder, a theologian named Novatian (c. 200–258).  It was a rigorist movement that held a strict view that refused readmission to communion of lapsi, those baptized Christians who had denied their faith during the persecution of Emperor Decius.  After his ascension, Decius had ordered everyone in the Empire to demonstrate loyalty to Rome by offering incense to the cult images of deities.  Many Christians refused, including Pope Fabian, who was martyred in 250 A.D.  Fabian was interred in the catacomb of Callixtus in Rome with the Greek inscription “Fabian, Bishop, Martyr” on his tomb which survives today.  

After his death, Pope Cornelius was elected Fabian’s successor, but Novatian opposed the election of Pope Cornelius on the grounds that Cornelius was too liberal in accepting lapsed Christians. Novatian was heavily influenced by Tertullian, who had also been a rigorist.  Novatian held that lapsed Christians, who had not maintained their confession of faith under persecution, may not be received again into communion with the church. He set himself up as an anti-pope and was consecrated bishop by three bishops of Italy and declared himself to be the true Pope.  He and his followers were excommunicated by a synod held at Rome and the Church of Rome declared the Novatianists heretical following the letters of Saint Cyprian of Carthage.  Novatian is said to have suffered martyrdom under Emperor Valerian I (253–60).  In the 4th and 5th centuries, the Donatist sect in Africa Proconsulare maintained a similar belief about Christians who had lapsed under the pressures of persecution; they too were declared heretics.

Source: 

• Papandrea, James L. The Trinitarian Theology of Novatian of Rome: A Study in Third-Century Orthodoxy. Lewiston, NJ, 2008.