What is "patripassianism"

Patripassian \Pa`tri*pas"sian\, n. [LL. Patripassiani, pl.; L. pater father + pati, passus, to suffer: cf. F. patripassiens.] (Eccl. Hist.) One of a body of believers in the early church who denied the independent pre["e]xistent personality of Christ, and who, accordingly, held that the Father suffered in the Son; a monarchian. -- Pa`tri*pas"sian*ism, n.

In Christian theology, patripassianism (as it is referred to in the Western church) or Sabellianism in the Eastern church (also known as modalism, modalistic monarchianism, or modal monarchism) is the nontrinitarian or anti- trinitarian belief that God the Father, Jesus Christ, and the Holy Spirit are three different modes or aspects of one monadic God, as perceived by the believer, rather than three distinct persons within the Godhead - that there are no real or substantial differences between the three, such that there is no substantial identity for the Spirit or the Son.

In the West, this belief was known as patripassianism (from Latin patri- "father" and passio "suffering"), because the teaching required that since the Father had become incarnate in Christ, he had suffered.