From St. Athanasius . . .
(St. Athanasius speaks of victory Jesus has come to win for us in the body born at Christmas.)
For now that He has come to our realm, and taken up his abode in one body among His peers, henceforth the whole conspiracy of the enemy against mankind is checked, and the corruption of death which before was prevailing against them is done away. For the race of men had gone to ruin, had not the Lord and Saviour of all, the Son of God, come among us to meet the end of death.
[from: "On the Incarnation of the Word," §9.4
in Nicene and Post-Nicene Fathers, Second Series, Vol. 4, p. 41.]