Some Montanists fell into the “Sabellian” heresy, which taught that Father, Son and Holy Spirit were not three distinct persons, but only one person acting in three different ways.18 The majority of Montanists were in fact orthodox in their doctrine of the Trinity; their greatest theologian, Tertullian, was an ardent foe of Sabellianism, and the fierce Roman enemy of Montanism, Praxeas, was a Sabellian himself!19 However unfairly, though, the Sabellianism of the minority of Montanists gave their opponents a perfect opportunity to brand the whole movement as heretical in its doctrine of God.
