“Consubstantial with the Father”
Consubstantial (Latin: consubstantialis) is an adjective used in Latin Christian christology, coined by Tertullian in Against Hermogenes 44, used to translate the Greek term homoousios. “Consubstantial” describes the relationship among the Divine persons of the Christian Trinity and connotes that God the Father, God the Son, and God the Holy Spirit are “of one being” in that the Son is “generated” (“born” or “begotten”) “before all ages” or “eternally” of the Father’s own being, from which the Spirit also eternally “proceeds.” (Wikipedia)
An Explanation (Father Romanus Cessario, o.p., serves as senior editor for Magnificat and teaches theology at St. John’s Seminary in Boston.)
For the last 40 years or so, Catholics have become accustomed to express their belief in the sameness of the Father and the Son by the expression, “one in Being with the Father.” This translation came about because certain experts had opined that a literal translation of the Latin term “consubstanialem,” that is, consubstanital, would be too unfamiliar to the everyday churchgoer.
However, the expression “one in Being with the Father” does not translate “consubstantialem.” The expression is too vague. Since God creates and sustains all that exists, everything in some sense can be said to be one in being with God. Not that everything is the divine nature but that everything outside of God remains dependent on the divine nature for its borrowed existence. The sameness that the Eternal Son enjoys with the Father is not like that. Instead, this sameness arises from the specific substance or nature of the Godhead. Catholic faith holds that each of the three Divine Persons share one and the same divine nature or substance. Just as the mystery of the Blessed Trinity stands at the heart of our belief, so also it grounds our salvation.
The Greek expression adopted at the Council of Nicaea is “homoousious,” which is translated into English as “con-substantial.” The Eternal Son, who was born of the Virgin Mary, is neither “like” the Father nor “practically the same substance” as the Father. The Eternal Son enjoys the very same substance as the Father. The Son possesses fully the Godhead of the Father. So today, the Church again confesses in the English rendition of the Creed that Jesus Christ is “consubstantial with the Father.” (Father Romanus Cessario, o.p., serves as senior editor for Magnificat and teaches theology at St. John’s Seminary in Boston.)