The Christian doctrine of the Trinity (Latin: Trinitas, lit
’triad’, from Latin: trinus ’threefold’) defines God as being one god existing in three coequal, coeternal, consubstantial divine persons: God the Father, God the Son (Jesus Christ) and God the Holy Spirit, three distinct persons sharing one homoousion (essence)
In this context, the three persons define who God is, while the one essence defines what God is
This doctrine is called Trinitarianism and its adherents are called trinitarians, while its opponents are called antitrinitarians or nontrinitarians
Nontrinitarian positions include Unitarianism, Binitarianism and Modalism
While the developed doctrine of the Trinity is not explicit in the books that constitute the New Testament, the New Testament possesses a triadic understanding of God and contains a number of Trinitarian formulas
The doctrine of the Trinity was first formulated among the early Christians and fathers of the Church as early Christians attempted to understand the relationship between Jesus and God in their scriptural documents and prior traditions