binitarianism

Etymology
From.

Noun

 * 1)  The belief, particularly among some Christian churches (also called cults, denominations, or sects) that God is two personae (persons), two individuals, or two aspects in one Godhead (or God), these being God the Father and God the Son (Jesus Christ).

Usage notes
A historical example of binitarianism is those sects that endorsed Macedonianism, also known as the Pneumatomachi, who did not see the Holy Spirit as God or at least equal to the Son and Father.

Translations

 * German: Binitarismus, Binitarianismus, Zweieinigkeitslehre
 * Polish: binitarianizm
 * Romanian: binitarianism
 * Turkish: biniteryanizm