Revelation 3:21 (NRSV) — Theosis

May grace and peace be yours in abundance in the knowledge of God and of Jesus our Lord. His divine power has given us everything needed for life and godliness, through the knowledge of him who called us by his own glory and goodness. Thus he has given us, through these things, his precious and very great promises, so that through them you may escape from the corruption that is in the world because of lust, and may become participants of the divine nature. For this very reason, you must make every effort to support your faith with goodness, and goodness with knowledge, and knowledge with self-control, and self-control with endurance, and endurance with godliness, and godliness with mutual affection, and mutual affection with love. For if these things are yours and are increasing among you, they keep you from being ineffective and unfruitful in the knowledge of our Lord Jesus Christ. For anyone who lacks these things is nearsighted and blind, and is forgetful of the cleansing of past sins. Therefore, brothers and sisters, be all the more eager to confirm your call and election, for if you do this, you will never stumble.

Maximus the Confessor

God the Son of the Father became son of man and man Himself for this reason, to make men gods and sons of God.

Basil the Great

Just as when a sunbeam falls on bright and transparent bodies, they themselves become brilliant too, and shed forth a fresh brightness from themselves, so souls wherein the Spirit dwells, illuminated by the Spirit, themselves become spiritual, and send forth their grace to others. Hence comes foreknowledge of the future, understanding of mysteries, apprehension of what is hidden, distribution of good gifts, the heavenly citizenship, a place in the chorus of angels, joy without end, abiding in God, the being made like to God, and, highest of all, the being made God.