Against Sola Scriptura

Athanasius Discourse 1 Against the Arians par 3 (296-373)
Yes surely; while all of us are and are called Christians after Christ, Marcion broached a heresy a long time since and was cast out; and those who continued with him who ejected him remained Christians; but those who followed Marcion were called Christians no more, but henceforth Marcionites. Thus Valentinus also, and Basilides, and Manichaeus, and Simon Magus, have imparted their own name to their followers; and some are accosted as Valentinians, or as Basilidians, or as Manichees, or as Simonians; and other, Cataphrygians from Phrygia, and from Novatus Novatians. So too Meletius, when ejected by Peter the Bishop and Martyr, called his party no longer Christians, but Meletians(2), and so in consequence when Alexander of blessed memory had cast out Arius, those who remained with Alexander, remained Christians; but those who went out with Arius, left the Saviour's Name to us who were with Alexander, and as to them they were hence-forw