“For this was the very end and purpose of His Incarnation, that our human nature might in His Person obtain and receive whatever it could not otherwise have obtained, and that we might be partakers both of the same nature and of the same blessings within Him... It was necessary, therefore, that God and man should be personally united, in order that human nature might be invested with power and exalted to glory” The Orations of St. Athanasius Against the Arians (London: Griffith, Farran, Okeden & Welsh), IV.6; cf. III.34, and II.70.
“As, on the one hand, we could not have been redeemed from sin and the curse, unless the flesh and nature, which the Word took upon Him had been truly ours (for we should have had no interest by his assumption of any foreign nature); so also man could not have been united to the Divine nature, unless that Word, which was made flesh, had not been, in essence and nature, the Word and Son of God. For that was the very purpose and end of our Lord’s Incarnation, that He should join what is man by nature to Him who is by nature God, that so man might enjoy His salvation and His union with God without any fear of its failing or decrease” The Orations of St. Athanasius Against the Arians (London: Griffith, Farran, Okeden & Welsh), II.70; cf. III.34, and IV.6.
“For that which He has not assumed He has not healed; but that which is united to His Godhead is also saved. If only half Adam fell, then that which Christ assumes and saves may be half also; but if the whole of his nature fell, it must be united to the whole nature of Him that was begotten, and so be saved as a whole,” Gregory Nazianzen, A Select Library of the Nicene and Post-Nicene Fathers of the Christian Church, second series, vol. VII (Edinburgh: T&T Clark), Ep. CI.