cyril_alexandriaIn that day ye shall know that I am in My Father, and ye in Me, and I in you (John 14:20).

After the creature [man]…had attained unto the propriety of its perfect nature by means of both soul and body…, then like a stamp of His own Nature the Creator impressed on it the Holy Spirit – the Breath of Life.

Thus the creature became moulded unto the archetypal Beauty, and completed after the image of Him that created it, enabled unto every form of excellence, by virtue of the Spirit given to dwell in it.

Having free will, and entrusted with the reins of its own purposes – for this also is an element in the image, forasmuch as God has power over His own purposes – the creature turned and has fallen.

God the Father both determined and took in hand to gather together once more in Christ the nature of man unto its ancient estate, and, willing it, He accomplished it.

[…] It was not otherwise possible for man, forasmuch as he was of a nature that was perishing, to escape death, save by recovering that ancient grace, and partaking once more in God.

For God holds all things together in being and preserves them in life through the Son in the Spirit.

Therefore He has become partaker of blood and flesh. He has become man, being by nature Life, and begotten of the Life that is by nature, of God the Father.

He is the Father’s Only-begotten Word, Who became man in order that, uniting Himself with the flesh that by the law of its own nature was perishing, He might bring it back unto His own Life and make it through Himself partaker of God the Father.

For He is Mediator between God and men, according as it is written, knit unto God the Father naturally as God and of Him, and again unto men as man; and withal having in Himself the Father and being Himself in the Father.

For He is the impress and effulgence of His Person, and not distinct from the Essence, whereof He is impress and wherefrom He proceeds as effulgence.

[…] And He wears our nature, remoulding it unto His own Life. And He is also Himself in us; for we have all been made partakers of Him, and have Him in ourselves through the Spirit.

Thus we have Both, being made partakers of the Divine Nature, and are entitled sons, in this way having in us also the Father Himself through the Son.

And Paul will testify hereof where he says: Because ye are sons, God sent forth the Spirit of His Son into your hearts, crying, Abba, Father. 

Cyril of Alexandria (c. 376-444): Commentary on St John’s Gospel, book 9 [on John 14:20].