35 But we must not forget what follows the subjection, namely, Last of all is death conquered by Him. This victory over death is nothing else than the resurrection from the dead: for when the corruption of death is stayed, the quickened and now heavenly nature is made eternal, as it is written, For this corruptible must put on incorruption, and this mortal must put on immortality. But when this mortal shall have put on immortality, then shall come to pass the saying that is written, Death is swallowed up in strife.
O death, where is your sting? O death, where is your strife ? In the subjection of His enemies death is conquered; and, death conquered, life immortal follows. The Apostle tells us also of the special reward attained by this subjection which is made perfect by the subjection of belief: Who shall fashion anew the body of our humiliation, that it may be conformed to the body of His glory, according to the works of His power, whereby He is able to subject all things to Himself. There is then another subjection, which consists in a transition from one nature to another, for our nature ceases, so far as its present character is concerned, and is subjected to Him, into Whose form it passes.
But by 'ceasing' is implied not an end of being, but a promotion into something higher. Thus our nature by being merged into the image of the other nature which it receives, becomes subjected through the imposition of a new form.
Source: On the Trinity (New Advent)