Siballists

Early Christians were mockingly called Sibyllists (Sibyllistae or Σιβυλλισταί, meaning "sibyl-mongers" or "believers in sibyls") by pagan critics like the 2nd-century philosopher Celsus. 

Why the Name Was Used

Prophetic Writings: The term comes from sibulla (Greek for prophetess or seer). Early Christians heavily referenced and even expanded upon the Sibylline Oracles—collections of Greek and Roman prophetic hexameter verse. 

Apocalyptic Preaching: Pagan opponents mocked believers as "sibyl-mongers" because Christians used these pagan-style prophecies and the Book of Revelation in their missionary work to argue that even classical seeresses had foretold the Christian God. 

Adoption by Church Fathers: While critics used it as an insult, respected Christian writers like Clement of Alexandria and Lactantius later embraced the Sibyl as a valid ancient witness who foreshadowed Christ.

Sibyllists was an early derogatory term used by pagans to mock Christians who cited the Sibylline Oracles during religious debates. 

Why Pagans Used the Name

Reliance on Oracles: Early Christians used verses from the Sibylline Oracles to prove Christian truths to non-Christians.

The Mockery: Pagans called Christians "Sibyllists" to dismiss them as followers of pagan prophetesses rather than true scripture. 

Christian Views on the Sibyl

Accepted Authority: Christian writers like Clement of Alexandria viewed the Sibyl as a real prophet inspired by God.

Prophesying Christ: The texts contained verses that supposedly predicted the life and crucifixion of Jesus Christ.

Artistic Legacy: The acceptance of these prophetic figures lasted into the Renaissance, famously inspiring Michelangelo's paintings of Sibyls on the Sistine Chapel ceiling.