Isaias 7:14

The cross of Christ is indeed a stumbling-block to those that do not believe, but to the believing it is salvation and life eternal. “Where is the wise man? where the disputer?” Where is the boasting of those who are called mighty? For the Son of God, who was begotten before time began, and established all things according to the will of the Father, He was conceived in the womb of Mary, according to the appointment of God, of the seed of David, and by the Holy Ghost. For says [the Scripture], “Behold, a virgin shall be with child, and shall bring forth a son, and He shall be called Immanuel.” He was born and was baptized by John, that He might ratify the institution committed to that prophet.

The prophets also, when they speak as in the person of God, [saying,] “I am God, the first [of beings], and I am also the last, and besides Me there is no God,” concerning the Father of the universe, do also speak of our Lord Jesus Christ. “A Son,” they say, has been given to us, on whose shoulder the government is from above; and His name is called the Angel of great counsel, Wonderful, Counsellor, the strong and mighty God.” And concerning His incarnation, “Behold, a virgin shall be with Child, and shall bring forth a Son; and they shall call his name Immanuel.” And concerning the passion, “He was led as a sheep to the slaughter; and as a lamb before her shearers is dumb, I also was an innocent lamb led to be sacrificed.”

For there is but One that became incarnate, and that neither the Father nor the Paraclete, but the Son only, [who became so] not in appearance or imagination, but in reality. For “the Word became flesh.” For “Wisdom builded for herself a house.” And God the Word was born as man, with a body, of the Virgin, without any intercourse of man. For [it is written], “A virgin shall conceive in her womb, and bring forth a son.” He was then truly born, truly grew up, truly ate and drank, was truly crucified, and died, and rose again. He who believes these things, as they really were, and as they really took place, is blessed. He who believeth them not is no less accursed than those who crucified the Lord. For the prince of this world rejoiceth when any one denies the cross, since he knows that the confession of the cross is his own destruction. …

And hear again how Isaiah in express words foretold that He should be born of a virgin; for he spoke thus: “Behold, a virgin shall conceive, and bring forth a son, and they shall say for His name, ‘God with us.’ ” For things which were incredible and seemed impossible with men, these God predicted by the Spirit of prophecy as about to come to pass, in order that, when they came to pass, there might be no unbelief, but faith, because of their prediction. But lest some, not understanding the prophecy now cited, should charge us with the very things we have been laying to the charge of the poets who say that Jupiter went in to women through lust, let us try to explain the words. This, then, “Behold, a virgin shall conceive,” signifies that a virgin should conceive without intercourse. …

2. For this reason [it is, said], “Who shall declare His generation?” since “He is a man, and who shall recognise Him?” But he to whom the Father which is in heaven has revealed Him, knows Him, so that he understands that He who “was not born either by the will of the flesh, or by the will of man,” is the Son of man, this is Christ, the Son of the living God. For I have shown from the Scriptures, that no one of the sons of Adam is as to everything, and absolutely, called God, or named Lord. But that He is Himself in His own right, beyond all men who ever lived, God, and Lord, and King Eternal, and the Incarnate Word, proclaimed by all the prophets, the apostles, and by the Spirit Himself, may be seen by all who have attained to even a small portion of the truth. Now, the Scriptures would not have testified these things of Him, if, like others, He had been a mere man. …

1. God, then, was made man, and the Lord did Himself save us, giving us the token of the Virgin. But not as some allege, among those now presuming to expound the Scripture, [thus:] “Behold, a young woman shall conceive, and bring forth a son,” as Theodotion the Ephesian has interpreted, and Aquila of Pontus, both Jewish proselytes. The Ebionites, following these, assert that He was begotten by Joseph; thus destroying, as far as in them lies, such a marvellous dispensation of God, and setting aside the testimony of the prophets which proceeded from God. For truly this prediction was uttered before the removal of the people to Babylon; that is, anterior to the supremacy acquired by the Medes and Persians. …

4. For the one and the same Spirit of God, who proclaimed by the prophets what and of what sort the advent of the Lord should be, did by these elders give a just interpretation of what had been truly prophesied; and He did Himself, by the apostles, announce that the fulness of the times of the adoption had arrived, that the kingdom of heaven had drawn nigh, and that He was dwelling within those that believe on Him who was born Emmanuel of the Virgin. …

Begin we, therefore, to prove that the Birth of Christ was announced by prophets; as Isaiah ( e.g. ,) foretells, “Hear ye, house of David; no petty contest have ye with men, since God is proposing a struggle. Therefore God Himself will give you a sign; Behold, the virgin shall conceive, and bear a son, and ye shall call his name Emmanuel” (which is, interpreted, “God with us”): “butter and honey shall he eat;”: “since, ere the child learn to call father or mother, he shall receive the power of Damascus and the spoils of Samaria, in opposition to the king of the Assyrians.”

And challenge us first, as is your wont, to consider Isaiah’s description of Christ, while you contend that in no point does it suit. For, to begin with, you say that Isaiah’s Christ will have to be called Emmanuel; then, that He takes the riches of Damascus and the spoils of Samaria against the king of Assyria. But yet He who is come was neither born under such a name, nor ever engaged in any warlike enterprise. I must, however, remind you that you ought to look into the contexts of the two passages. For there is immediately added the interpretation of Emmanuel, “God with us;” so that you have to consider not merely the name as it is uttered, but also its meaning. The utterance is Hebrew, Emmanuel , of the prophet’s own nation; but the meaning of the word, God with us , is by the interpretation made common property. …

You are equally led away by the sound of names, when you so understand the riches of Damascus, and the spoils of Samaria, and the king of Assyria, as if they portended that the Creator’s Christ was a warrior, not attending to the promise contained in the passage, “For before the Child shall have knowledge to cry, My father and My mother, He shall take away the riches of Damascus and the spoil of Samaria before the king of Assyria.” You should first examine the point of age, whether it can be taken to represent Christ as even yet a man, much less a warrior. …

The sick of the palsy is healed, and that in public, in the sight of the people. For, says Isaiah, “they shall see the glory of the Lord, and the excellency of our God.” What glory, and what excellency? “Be strong, ye weak hands, and ye feeble knees:” this refers to the palsy. “Be strong; fear not.” Be strong is not vainly repeated, nor is fear not vainly added; because with the renewal of the limbs there was to be, according to the promise, a restoration also of bodily energies: “Arise, and take up thy couch;” and likewise moral courage not to be afraid of those who should say, “Who can forgive sins, but God alone?” So that you have here not only the fulfilment of the prophecy which promised a particular kind of healing, but also of the symptoms which followed the cure. In like manner, you should also recognise Christ in the same prophet as the forgiver of sins. …

But, leaving Alexander with his syllogisms, which he so perversely applies in his discussions, as well as with the hymns of Valentinus, which, with consummate assurance, he interpolates as the production of some respectable author, let us confine our inquiry to a single point, Whether Christ received flesh from the virgin? that we may thus arrive at a certain proof that His flesh was human, if He derived its substance from His mother’s womb, although we are at once furnished with clear evidences of the human character of His flesh, from its name and description as that of a man, and from the nature of its constitution, and from the system of its sensations, and from its suffering of death. Now, it will first be necessary to show what previous reason there was for the Son of God’s being born of a virgin. …