Gregory of Nyssa

Since then it was impossible that our life, which had been estranged from God, should of itself return to the high and heavenly place, for this cause, as saith the Apostle, He Who knew no sin is made sin for us, and frees us from the curse by taking on Him our curse as His own, and having taken up, and, in the language of the Apostle, "slain" in Himself "the enmity" which by means of sin had come between us and God,—(in fact sin was "the enmity")—and having become what we were, He through Himself again united humanity to God. For having by purity brought into closest relationship with the Father of our nature that new man which is created after God, in Whom dwelt all the fulness of the Godhead bodily, He drew with Him into the same grace all the nature that partakes of His body and is akin to Him. And these glad tidings He proclaims through the woman, not to those disciples only, but also to all who up to the present day become disciples of the Word,—the tidings, namely, that man is no longer outlawed, nor cast out of the kingdom of God, but is once more a son, once more in the station assigned to him by his God, inasmuch as along with the first-fruits of humanity the lump also is hallowed.