When describing the Trinity as One Being (μία οὐσία), Three Persons (τρεῖς ὑποστάσεις), Athanasius provides a very straight forward explanation to help us grasp what this might mean. Some people are confused as to how we can call God ‘One,’ when they are in fact, ‘Three.’ When I was young, we used the term,’man,’ to describe collectively the human race. ‘Man,’ was the same term we use today for, ‘humanity.’ Both are singular terms that describe the whole of the human race. These humans are of the same created being (ὁμοούσία). We may have different races across the world and a myriad of personalities but we are all human ‘beings’ ie of the same οὐσία. Anatomically we are the same in being and nature. Now if we look at ‘persons’ (ὑποστάσεις), say Stuart, Bruce and Baxter, we are describing three people who are of the same οὐσία but are persons in there own right, distinct from each other. Stuart is not Bruce or Baxter, Bruce is not Stuart or Baxter and Baxter is not Bruce or Stuart. However, they are all of the same being with each other as well as the rest of the human race. In Stuart, Baxter and Bruce’s case were have three distinct ‘persons’ ie three hypostasis (ὑπόστασισ) who are of the same beings ie human beings (ὁμοούσια). God is beyond created being as Athanasius would say. Beyond all created being ie humanity (οὐσία) there is the divine Being (οὐσία). As humanity is collectively ‘one’ so it is with God ie “Hear O Israel, the Lord our God, the Lord is one.” However, within this One οὐσία or Being are Three Persons (ὑποστάσεις), who are of the same being (ὁμοούσία), Father, Son and Holy Spirit, One Being (μία οὐσία), Three Persons (τρεῖς ὑποστάσεις). What is expressed here is this: as the very stuff of what it is to be human is common to all human beings, so the very stuff of what it is to be God is common to all Three Persons of the Trinity. The Father is God but He is not Jesus, the Word or the Holy Spirit. Jesus Christ the Word is not the Father or the Holy Spirit and the Holy Spirit is not Jesus Christ the Word or the Father. What is common to all Three Persons is the very stuff of what is means to be God is common to all Three. This is the necessary backdrop to understand more fully the humiliation of the Word, Jesus Christ.
Human beings are created beings. What is common to all of us is we are mortal, perverted, corrupt, degenerate, whose beings are enslaved to sin. We are bound by limitations as a result of the fall that prevent us from breaking free from the curse. The scope of the human condition we inherited in Adam is universal and it was into this human condition that the Word had condescended Himself into. Without ceasing to be God, the Word put on our flesh and became human taking on all that we are in our sinful alienation to God. He not only became human but He also subjected Himself to the limitations of our humanity and subjected Himself to its laws. Even though Jesus condescended Himself into our human condition, He remained who He was in His divine being, united to the Father. This is define with clarity by the terms homoousios to Patri (ὁμοούσιος τῷ Πατρί). He brought with Him all the knowledge of the Father as the precise reflection (χαρακτήρ) of His Innermost person (ὑπόστασις) (Hebrews 1.3) and proceeded to share all that the Father is with the nation of Israel.
There are many in Christian circles who avidly declare that Jesus Christ is God, which is what the ancient church vigorously defended. Yet, in declaring Jesus to be God, they often strip Him of the implications of His divinity so that He almost becomes a creature with divine powers. When we do this, then we reduce and distort the true meaning of the Incarnation to the degree that the foundation of the gospel is completely eroded. Jesus was both God and Man. In the ancient Church, God is the Source and the Cause for the whole of creation. In John’s prologue, Hebrews 1:1-3 and Colossians 1:15-20 there is a clear description of who Jesus Christ was. In short, He is the Word who was with God, in God, was God. Jesus Christ is precisely what God would say and do. He is precisely what the Father would say and do. He is the One who upholds all things by His powerful Word. He is the One through whom all things, visible and invisible, were created and in Him all things are held together. This is what Jesus Christ was before the Incarnation and this is what Jesus Christ remained to be after He became human. This was not just a Christian concept. There were many parts of the secular community who believed there was something or someone behind the universe that was the source and had caused creation to ‘be.’ Paul spoke to the Greeks as Athens and said in Acts 17:28, ‘. . . for in Him we live and move and exist (or have our being), as even some of your own poets have said, for we also are His children,’ indicating there was some cross-pollination of ideas about God. The Incarnation announced by those first Christians to the Mediterranean world was an explosive, foolish scandal. It was widely thought the Incarnation of any deity was absolutely impossible. According the Christians, this belief was turned on its head. What the pagans heard was the One behind the universe, what was understood to be its Source and Cause has become human. This was the first part of the scandal. The second part of the scandal was this Source and Cause who the Christians called Jesus Christ, was crucified.
In the Incarnation, the οὐσία or Being of the Word, while remaining ὁμοούσία or, of the same Being, with the Father, united Himself with the οὐσία or being of fallen Adamic humanity where the Being of the Word and the Being of Jesus became one (ἐνανθρωπήσεως). It was not two Persons, (or two ὑποστάσεις) one the Divine Word and the other His humanity. Rather, it is the Divine Word Incarnating, not in a Man, but as Man (ἀνθρωπίνος). He remains all Man and all God but one ὑπόστασις. Jesus Christ remained the Word who was with God but also has now become man. Furthermore, Jesus Christ upholds all things by His powerful Word (Heb. 1:3), is the One through whom all things were created and it is in Him all things are held together (Col. 1.16-17). This means Jesus Christ is united with every single human being. As a result, He is the suitable High Priest who can stand in our place and act accordingly on our behalf, all for our sake. Furthermore, Jesus is the High Priest who offers Himself as the suitable sacrifice, ie the Offerer and the Offering.
While Jesus humbled Himself within the limitations and adopting the rules of what it meant to be human, in so doing, He took on all the ills of our humanity that had driven a wedge between ourselves and God but remained Himself united to the Father and to humanity. This is humanity in its disobedience, ravaged by sin, held in the grip of death, in its weakness, poverty, darkness, depravity, ignorance, misery and its frail mortality to the uttermost depths of its fallen being. How can someone so Holy allow such filth to stain His own divinity? Playing strictly within the rules of His humanity, the holiness of Jesus Christ took on our fallen depraved nature and cleansed it through His sinless sanctifying life and recreated it. He plunged Himself into the midst of human darkness. Whereas our beings are extinguished by the darkness, the Light of Christ’s Divine Being could not be overpowered by it. Right here, we have the blessed exchange whereby the whole of humanity, body, mind and soul has been taken up and healed. This is how the love of God has been expressed. He saw the plight of the human race, came to our aid by becoming one of us, taking on all that we are so that through Him we are brought back where we ought to be.
Therefore, since the children share in flesh and blood, He Himself likewise also partook of the same, that through death He might render powerless him who had the power of death, that is, the devil, and might free those who through fear of death were subject to slavery all their lives. For assuredly He does not give help to angels, but He gives help to the descendant of Abraham. Therefore, He had to be made like His brethren in all things, so that He might become a merciful and faithful high priest in things pertaining to God, to make propitiation for the sins of the people. For since He Himself was tempted in that which He has suffered, He is able to come to the aid of those who are tempted.
Our existence was held on a knifes edge always ready to plunge into oblivion. So Jesus Christ gave His own life in exchange for ours, the body, soul and mind, grounding its existence in the very existence of Christ’s own divine Being, a life which cannot be extinguished. Thus the humanity that was opposed to God was healed through the work of the whole life of Jesus Christ from the Incarnation to the rolling away of the stone. He lowered His divine existence into the frail existence of fallen humanity securing it in His own divine Being. He beat His way forward throughout His whole life while living the life we ought to have lived, in our place and for our sake. He was crucified, buried, resurrected and ascended to the right-hand of the Father. Because our existence was united to God’s own existence in Jesus Christ, humanity were included in the life of Jesus Christ. Therefore we were also crucified, buried with Him and were resurrected and ascended to the right-hand of the Father. Gregory Nazianzen said it this way:
Let us become like Christ, since Christ became like us. Let us become God’s for His sake, since He for ours became Man. He assumed the worse that He might give us the better; He became poor that we through His poverty might be rich; He took upon Him the form of a servant that we might receive back our liberty; He came down that we might be exalted; He was tempted that we might conquer; He was dishonoured that He might glorify us; He died that He might save us; He ascended that He might draw to Himself us, who were lying low in the Fall of sin. Let us give all, offer all, to Him Who gave Himself a Ransom and a Reconciliation for us. But one can give nothing like oneself, understanding the Mystery, and becoming for His sake all that He became for ours (Oration 1.5) (compare also Athanasius Con Arianos 1.41 & 4.6-7; De decretis 14)
Even further than this, the Incarnation meant, the incomprehensible God could now be comprehended through His conversing with us in the flesh. These conversations have been recorded in the gospels. This one Human Being is the only One who knows the Father. It takes God to know God and without God, God cannot be known and therefore it is God who must teach (Irenaeus, Against Heresies 4.6.4). The Eternal One presented Himself in time and space, in our human history and taught us the things of Himself. Through His birth via the Virgin Mary, He made her ancestry His own ancestry. All aspects of corrupted human nature and its capacity to suffer, He brought into the incorruptible and impassible. Above all the greatest enemy to humanity was defeated through His own death and the devil stripped of all its power. It was only because of God’s overwhelming love for the human race, His φιλανθροπία, or philanthropy, which the fathers often used to describe the all-powerful generosity of loving kindness towards humanity, that He would place Himself at such a lowly state in solidarity with us so that He could freely give back what had been stolen from us at the Fall. This truly is the Good News the world needs to know.