Christian Homoousia is a theological term that was introduced during the Arian controversy in the fourth century. It means “of the same substance” or “consubstantial” and refers to the belief that Jesus Christ is of the same substance as God the Father, and therefore fully divine.
The concept of Homoousia was developed in response to the teachings of Arius, who claimed that Jesus was a created being and not co-equal with the Father. The orthodox Christian Church rejected this view and affirmed that Jesus was fully divine, sharing the same substance or essence as the Father.
The idea of Homoousia was eventually enshrined in the Nicene Creed, which was adopted at the First Council of Nicaea in 325 AD. The Creed states that Jesus is “begotten, not made, of one substance (Homoousia) with the Father.”
Today, the concept of Homoousia is a fundamental tenet of orthodox Christian theology and is accepted by most Christian denominations, including the Catholic Church, Eastern Orthodox Church, and many Protestant denominations.