One Substance with the Father
Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, (Matt. 28:19)
"How many do they worship?"
This question was asked of me by a representative from a neighboring church.
"One or three depending on how you count," I replied. The man looked horrified.
"So few? How do they stay open?" He immediately asked. I had my laugh and explained to him that while he had meant to ask how many people attended worship in a specific congregation, I had answered the question concerning who we worship.
The concept of one God that is simultaneously three persons has long baffled many from within and outside of the church. God is beyond human understanding, and the manner in which He reveals Himself to us cannot simply be set aside with a shrug of the shoulders, and complacent statements like, "Who can understand this" or "We see through a glass darkly, so you are free to believe and teach what you like."
The truth is, how we understand the relationships between Jesus, the Father and Holy Spirit will have a great impact in what we teach regarding the salvation of man. In particular, it’s essential we look at and understand Christ’s relationship to the Father because most of the controversy surrounding a proper confession of the Trinity has centered around the person of Jesus Christ and His connection to God
The early creeds, in particular, the Nicene Creed, tell us that Christ is “very God of very God, begotten not made, of one substance with the Father.” The Greek word for “one substance” is homoousios. As one substance, Christ is God become man, the fullness of God who was pleased to dwell in Jesus Christ (Col. 1:19). As the early church father and hero of Nicea, Athanasius, has taught us to confess, “for us men and for our salvation, Christ came down from heaven, conceived by the Holy Spirit, born of the Virgin Mary, was crucified died and was buried.”
In other words, Christ was born, lived and died as God and as man. God was born of the Virgin Mary. God died, and in doing so, He displayed the fullness of humanity by tasting the bitter cup that waits for all of us. As a man with flesh and blood of the same substance as your flesh and blood, Christ rose from the dead for our justification. As the God-man, He accomplished what we could not in both life and death so that our hope for salvation would rest in Him; not in our efforts to become godlike, nor our ability to mimic Him in our daily lives.
In contrast to the Biblical teaching of Christ’s two natures, Athanasius’ contemporary, Arius, taught that the Son was not of one substance with the Father, but was created by the Father. As God’s first creation, He was divine due only to His ability to live a perfect life. Thus, according to Arius, we are justified by following Jesus’ example, and the only way to be saved is by living a perfect life.
The heresy of Arianism was a huge issue for the early church, and the Nicene Creed was written to combat it. In the end, the church would adopt the Nicene Creed as Athanasius formulated it. But "of one substance" and the term, homoousios, would not be without controversy. Previously, the Church had rejected the term for its connection to Gnosticism and materialism, and it’s lack of biblical testimony. However, the biggest objection was that the word, homoousios, implied that Jesus and the Father were the same person, just wearing different masks.
It was the thought that if the Son and the Father shared the same substance, they must also necessarily be the same person, but that is not true. Two pennies are made of copper. They are distinct but have an antecedent substance of which they both partake. However, this line of reasoning would also become problematic. Athanasius claims the adoptionist Paul of Samasota used this reasoning in a reductio ad absurdum. Taken in this sense, the Father and the Son would not be the same, but two very different realities. This belief contradicted the monotheism displayed through Scripture; a doctrine shared by both Christianity and Judaism. When bishops assembled in Antioch in 268 AD, they deposed Paul of Samasota, and condemned not only his adoptionistic teachings (the teaching that Jesus was adopted as the son of God and given divine powers) but also his use of the word homoousios.
It would be Tertullian, a lawyer turned theologian, who would ultimately pave the way for Athanasius's redemption of the idea of one substance. He would note that substance could refer not only to material but also essence, he would also begin to talk about persons. So Father, Son, and Holy Spirit share one name, the being of God, and yet remain distinct personalities all of whom are co-eternal and indivisible one from the other.
After a long, historical battle, we still confess that Jesus is of one substance with the Father. In regards to the first commandment, this is a rather important matter. We worship Jesus Christ, and yet we are to have no other gods before God. If we are to continue to worship Christ and put our faith in Him, He must be God!
In Exodus, God justifies His demand in the First Commandment through the exodus from Egypt. He redeemed the Israelites by leading them out of Egypt. This is why the Israelites were to have no other gods before Him. No other “god” had ever interceded on behalf of slaves in this way. The same can be said of Jesus Christ. In Him, God calls us out of our bondage to the slave masters of sin, death and the devil by becoming man and dying for us. This allowed the blood of man to have the infinite value required not just to save one man, but all men and women, even as the blood of the paschal lamb saved the firstborn of the Israelites from the wrath of God. Christ’s shared substance shows us how loving God is, in that He would condescend to become just like us. This means we have a God worth worshiping, a God we can fear, love and trust even when our fears get the best of us; a God who frees us from slavery.
I am indebted to "The First Seven Ecumenical Councils" for the material in this essay and highly recommend this book which chronicles the history and development of Trinitarian theology.