When studying the origins of Theosis, many more patristic texts could be added from the Cappadocian fathers and others. The Cappadocians, as you will recall, heavily influenced not only the theology of the Eastern Church but also the ritual of our church. Basil attributes the experience of theosis to the Holy Spirit who, being God by nature, deifies by grace those who still belong to a nature subject to change. St. Macarius likewise accentuates the role of the Spirit in theosis when he says that persons to be deified, though they retain their own identity (i.e., they do not overstep the distinction between God and man) are all filled with the Holy Spirit.
Maximos the Confessor, another of the primary Greek Fathers, describes theosis or deification as a participation of the whole man in the whole God. Maximos states:
In the same way in which the soul and the body are united, God should become accessible for participation by the soul, through the soul’s intermediary, by the body, in order that the soul might receive an unchanging character, and the body, immortality; and finally that the whole man should become God, deified by the grace of God-become-man, becoming whole man, soul and body, by nature, and becoming whole God, soul and body, by grace.
Maximos continues by saying that a person who becomes obedient to God in all things hears God saying: ‘I said: you are gods’; he then is God and is called ‘God’ not by nature or by relation but by divine decree and grace. It is not, however, through her own activity or ’energy’ that a human being can be deified – this would be Pelagianism – but by divine “energy’; the two energies have a synergy that has an ontological basis in Christ.
As seems obvious, the Greek Fathers came to an understanding of theosis precisely because of how they understood the incarnation of God in the Person of Jesus. Once you understand that God’s incarnation was God’s revelation to humanity about how to achieve the fullness of life and become united with God, then the primary focus of life is to use the opportunities and challenges of life as a means to come to a deeper understanding of our relationship with our Creator and the meaning and purpose of this earthly existence. It is all about growing in our understanding that we have been created in the image and likeness of God.
What does it mean to you that you are created in God’s own image and likeness? This is the question that each of us must make an attempt to answer during this lifetime. The Great Fast is given to us in order to more fully focus our attention on finding an answer to this question.
The Eastern Church’s vision of salvation is different than the Western Church’s vision. For the Eastern Church salvation is intimately connected to Theosis, a real reason that we should make every effort to come to an understanding of this idea.