Against denying the birth: firstborn in every order

If he was not born, then he did not die either; and if he did not die, he has not risen from the dead; and if he has not risen from the dead, he has not triumphed over death or destroyed its dominion; and if death has not been conquered, how shall we rise to life — we who from the beginning fell under death’s blows? (1 Cor 15:17-22)

Those who will not admit the human being’s salvation, who do not believe God will raise them from the dead, also despise our Lord’s birth. The Word of God, having deigned to become flesh, submitted to this birth for us, in order to show the resurrection of the flesh and to have the primacy over all in heaven. (Col 1:18)

For he is the firstborn in the Father’s counsel, the perfect Word, governing and ordering all things on the earth by himself; he is the firstborn of the Virgin, a human being just, holy, devout, good, pleasing to God, perfect in all things, saving from Hades all who follow him; he is the firstborn from the dead and the guide who leads into the life of God. (Rom 8:29; Heb 2:10)