Warning against Modalism

This is a pertinent warning against a misunderstanding the concept of the Trinity that crept into the Church:

‘”Perhaps in overreaction to Arianism, Homoousian Christians eventually gave up the confession that the one God is the Father, and instead emphasized the divine nature as Christianity’s one God.

This shift in language was doomed to result in semi-modalism. In scripture, the “one God” is always a person, and such is the natural way to think of God: as personal. Scripture, however, as the early church did, specifies that this one God is the person of the Father in particular; the Son is His Son, the Holy Spirit, His Spirit.

(…)

The grounding of Christian monotheism is not that the Son and Spirit of God share His divine nature (although this is true), but that there is one supreme uncaused Cause of all, Who is one Supreme Authority over all, the Father.”

source: Andrew Davis, “Were the Homoiousians Right?” (contramodalism).

For the full warning, read this article.