Cyril on the Divine Nature

From a commentary on the gospel of John by Saint Cyril of Alexandria, bishop (d. 444 AD).
(Lib. 11, 11: PG 74, 559-562)

There is also another way of showing that we are made one by sharing in the Holy Spirit. If we have given up our worldly way of life and submitted once for all to the laws of the Spirit, it must surely be obvious to everyone that by repudiating, in a sense, our own life, and taking on the supernatural likeness of the Holy Spirit, who is united to us, our nature is transformed so that we are no longer merely men, but also sons of God, spiritual men, by reason of the share we have received in the divine nature. We are all one, therefore, in the Father and the Son and the Holy Spirit. We are in mind and holiness, we are one through our communion in the sacred flesh of Christ, and through our sharing in the one Holy Spirit.