Homoousion

Homoousion ( ; , from , , "same" and , , "being" or "essence") is a Christian theological term, most notably used in the Nicene Creed for describing Jesus (God the Son) as "same in being" or "same in essence" with God the Father (). The same term is also applied to the Holy Spirit in order to designate him as being "same in essence" with the Father and the Son. Those notions became cornerstones of theology in Nicene Christianity, and also represent one of the most important theological concepts within the Trinitarian doctrinal understanding of God.

==Terminology== The term (homoousion), the accusative case form of (, "consubstantial"), was adopted at the First Council of Nicaea (325) in order to clarify the ontology of Christ. From its Greek original, the term was translated into other languages. In Latin, which is lacking a present participle of the verb 'to be', two main corresponding variants occurred. Since the Aristotelian term was commonly translated in Latin as (essence) or (substance), the Greek term was consequently translated into Latin as or , hence the English terms coessential and consubstantial. Some modern scholars say that is properly translated as coessential, while consubstantial has a much wider spectrum of meanings. The Book of Common Prayer renders the term as "being of one substance with the Father."