A Trinitiarian error which denies the personal distinctiveness of the Father, Son and Spirit, either by denying Christ’s full deity or by teaching that the Father, the Son, and the Spirit are the same person in different “modes.”

Desiring to protect the monarchy (of the one God) from tritheism, some in the early church proposed the two major and opposing forms of Monarchism.  Dynamic, or adoptionistic, monarchism teaches that Jesus was not divine, but was a man fully endowed with the Holy Spirit (see Adoptionism).  Others, attempting to speak of the full deity of Christ, taught Modalism – that Son is the Father in a different mode.  Other forms of Modalism include Sabellianism and Patripassianism.

The following outlines the relational flow of the various Monarchistic Trinitiarian heresies: