Library Theodoret Compendium of Heretical Fables
Book 3
On the Quartodecimans
The heresy of the Quartodecimans has this premise. They say that the evangelist John, preaching in Asia, taught them to celebrate the feast of Pascha on the fourteenth of the moon; and, having poorly understood the apostolic tradition, they do not wait for the day of the Lord’s resurrection, but sometimes on the third, sometimes on the fifth, sometimes on the Sabbath, or however it happens, they keep festival in memory of the passion. They also use the spurious Acts of the Apostles and the other bastard writings—rather, alien to grace—which they call apocrypha. They also agree with those of Novatus; for these too turn away from the doctrine concerning repentance.
Greek: Theodoret of Cyrus, Haereticarum fabularum compendium / Αἱρετικῆς κακομυθίας ἐπιτομή (CPG 6223; PG 83, 336–556). English: study translation for BWAB Library—not a modern copyrighted translation. The full five books are hosted here.