Is Jesus a real man? by St. Cyril of Alexandria.

” “I wish to remind you, although you once knew all things, that Jesus having delivered the people from the land of Egypt, afterwards destroyed those, who did not believe; and the angels, who did not keep their own beginning, but left their own proper dwelling, have been kept by him in eternal chains in the darkness until the judgement of the great day” (Jude 5-6).

If the blessed Virgin gave birth to Jesus, as a mere man, but the disciple says of him that he delivered Israel from the bondage of the Egyptians, led the people through the desert and worked mighty miracles in the time of so many generations before the birth from the Virgin, where then will they say that he existed during those years? When did he acquire the beginning of his existence? For their own reasoning will not allow them to say that he obtained the beginning of his being from the virginal proceeding. Let then the inventors of these evil teachings explain when this man acquired the beginning of his generation; where and among whom did he pass so many years?

But no sound thinker will say any more that he is a mere man, who determined the punishment of those, who had sinned from of old and from the time that they deserted their own proper dwelling, and who gloriously delivered Israel from the hand of the Egyptians. If, then, according to what they maintain, Jesus can neither be conceived of as God the Logos, because he was born of the Virgin, nor as a man, because he performed these miracles (for these things, which have been mentioned, are alien to human nature and power), what essence and rank can they possibly imagine for him?”

Cyril of Alexandria,
Against those who are unwilling to confess that the Holy Virgin is Theotokos 5.