Patripassianism

In Christian theology, patripassianism (as it is referred to in the Western church) is a version of Sabellianism in the Eastern church and a form of modalism (modalistic monarchianism or modal monarchism). Modalism is the belief that God the Father, Jesus, and the Holy Spirit are three modes or emanations of one monadic God, as perceived by the believer, rather than three distinct persons within the Godhead; it holds that there are no real or substantial differences among the three, so the identity of the Spirit or the Son is that of the Father.

In the West, this belief was pejoratively called patripassianism by its critics (from Latin patri-, "father", and passio, "suffering") because they alleged that the teaching required that, since God the Father had become directly incarnate in Jesus, the Father literally sacrificed himself on the cross.