Fr Matt, here is something confirming what I have been saying about EO and Calvinism having the same idea regarding sanctification:
"The process of
becoming is not so much attributable to human effort
per se, but is a direct result of Jesus “transferring to Himself our erring generation.” And this is equally consistent with Western thinking, even though in term of
deification language coming from the East. The point is that even though 2 Peter may be a questionable book, and the language itself used to support the idea of theosis may be somewhat confusing — “partaking of the divine nature” — it may be concluded that all Peter and those among the church fathers, and the Eastern Orthodox, are saying is essentially what Protestants and Western theologians have advocated: Deification or the full realization of what God intended man to be is a sanctifying process whose inception began in the person of Jesus Christ at the cross, is nurtured along by the Holy Spirit, and culminated in the person of God the Father."
Theosis of the Early Church Fathers – Christian Apologetics Project