" My understanding of the (Eastern) Orthodox position here is not that it's a matter of declaration; it's a matter of being, correct? I am a layman not well educated as to the particulars of "sanctification" -- does this approach theosis (as described it seems to)?"
Its a grace driven process.
"'Can a man take fire into his bosom, and his clothes not be burned?' (Prov. 6:27) says the wise Solomon. And I say: can he, who has in his heart the Divine fire of the Holy Spirit burning naked, not be set on fire, not shine and glitter and not take on the radiance of the Deity in the degree of his purification and penetration by fire? For penetration by fire follows upon purification of the heart, and again purification of the heart follows upon penetration by fire, that is, inasmuch as the heart is purified, so it receives Divine grace, and again inasmuch as it receives grace, so it is purified. When this is completed (that is, purification of heart and acquisition of grace have attained their fullness and perfection), through grace a man becomes wholly a god." +Symeon the New Theologian
D'oh! I was way too overtired...