“… light of light, true God of true God, begotten not made….”
This phrase continues the thought of the previous one stating that Jesus Christ is born of the father (begotten, not made) and so is true God of true God. It goes on to say that Jesus is light and in Him is no darkness (I John 1:5)
“… God is light and in him is no darkness at all”
This concept of Jesus Christ as ‘light of light’ is expressed in the hymn we sing at Vespers (evening prayer):
“O Gladsome Light of the Holy Glory of the Immortal Father, Heavenly, Holy, Blessed Jesus Christ! Now that we have come to the setting of the sun and behold the light of evening, we praise God Father, Son and Holy Spirit. For meet it is at all times to worship Thee with voices of praise. O Son of God and Giver of Life, therefore all the world doth glorify Thee.”
“… of one essence with the Father…”
This phrase is the most technical and perhaps the most difficult of the Creed. The quote above is from the translation of the Creed we use in the Orthodox Church in America, but there are different translations also. Let us look at a few:
“… of one substance with the Father”
“… consubstantial with the Father”
“… one in being with the Father”
The word ‘essence’ or ‘substance’ means one nature, what one is. For example we have a human being, Mary. Mary’s substance or essence is what she is, that is, a human being. She has a human nature. So we can say the substance or essence is what a person is and person refers to who the person is. In other words, Mary is the person. So, God the Father, God the Son and God the Holy Spirit share the one, divine nature or essence, but they are three distinct persons in the Trinity.
One may ask why the Creed uses this technical, theological language. After all, “of one essence” is found nowhere in the Bible. Why do we need this technical language? The point is that Arius was willing to say that Jesus Christ is divine in some sense, but fundamentally was a creature. When one looks at the dividing line between the divine and human, between the maker and the made, according to Arius Jesus was on the human, created side. However, this phrase of the Creed states unmistakably that Jesus Christ is God in his very nature (Jesus also has a human nature but we will look at that point later). In other words, this phrase excludes anyone thinking that Jesus is a reature.
Even today there are many people who will say that Jesus Christ is a great spiritual or moral teacher, but not really God. But the phrase excludes the modern “Arius” as well.
The church had to write this in the Creed because it knows that if Jesus were not “true God of true God” He could not have fundamentally destroyed the power of sin, death and the devil. No created being, no matter how holy or wise, could not have done that. Only God can. So even if “of one essence” is a rather technical, theological language, it safeguards what the church has known from its being beginning, that Jesus Christ is God.