Ignatius of Antioch:
He who possesses the word of Jesus is truly able to hear even His very silence, that he may be perfect, and may both act as he speaks, and be recognised by his silence. There is nothing which is hid from God, but our very secrets are near to Him. Let us therefore do all things as those who have Him dwelling in us, that we may be His temples, and He may be in us as our God, which indeed He is, and will manifest Himself before our faces. Wherefore we justly love Him.
— Letter to the Ephesians, c.107 AD
“The relationship between Christ and His people is a substantial union — a union of our human nature with His resurrected and glorified human nature. This is not merely a moral union, a kind of pleasant fellowship with Christ. Baptism into Christ produces a dynamic union of substance with Him.” — Orthodox Study Bible, notes on Leviticus, pg. 144