I was reading Calvin's commentary on the letter to the Hebrews, in light of my recent exploration of this epistle, and I came across an interest comment on Heb 2.11:
ὅ τε γὰρ ἁγιάζων καὶ οἱ ἁγιαζόμενοι ἐξ ἑνὸς πάντες.
For the one who is sanctifying and the ones being sanctified are all of one.
Different translations understand the "of one" here differently. NIV interprets it "of one family"; NRSV interprets it "all have one Father." Calvin understands the phrase to refer rather to a common human nature:
Hence he says, that they are all of one, that is, that the author of holiness and we who are made partakers of it, are all of one nature, as I understand the expression. It is commonly understood of one Adam; and some refer it to God, and not without reason; but I rather think that one nature is meant, and one I consider to be in the neuter gender, as though he had said, that they are made out of the same mass.
Calvin goes on to say that this is a spiritually fruitful teaching:
It avails not, indeed, a little to increase our confidence, that we are united to the Son of God by a bond so close, that we can find in our nature that holiness of which we are in want; for he not only as God sanctifies us, but there is also the power of sanctifying in his human nature; not that it has it from itself, but that God had poured upon it a perfect fullness of holiness, so that from it we may all draw. And to this point this sentence refers, "For their sakes I sanctify myself." (John xvii. 19.) If, then, we are sinful and unclean, we have not to go far to seek a remedy; for it is offered to us in our own flesh.
The idea seems to be that the Son's incarnation and assumption of human nature has an effect on all of human nature, since it is shared among Christ and other human persons (cf. v. 14). Or at the very least it is available to those who've united themselves to Christ through baptism and the Eucharist. Thus there is a kind of empowerment of the person united to Christ in this very intimate way, so that she is strengthened from her own nature to rise above the quotidian impurity and unholiness which was her default state.
Here Calvin endorses what is typically a very Eastern notion, that Christ's incarnation has effected a fundamental change in human nature as such. This transformation strengthens and enables humanity to begin to embody the holiness which God desires. In more explicitly Eastern terms, the Son through his incarnation has sanctified and divinized humanity, so that humanity may undergo theosis or deification through unity with him. This is some ways off from that pessimistic Calvinism that posits no significant moral change or empowerment in the human person, and which harps on and on about our own miserable, utter depravity in comparison to Christ -- as if we weren't united with and empowered by him!