Against Heresies (Book III, Chapter 19)

Jesus Christ was not a mere man, begotten from Joseph in the ordinary course of nature, but was very God, begotten of the Father most high, and very man, born of the Virgin.

1. But again, those who assert that He was simply a mere man, begotten by Joseph, remaining in the bondage of the old disobedience, are in a state of death having been not as yet joined to the Word of God the Father, nor receiving liberty through the Son, as He does Himself declare: "If the Son shall make you free, you shall be free indeed." John 8:36 But, being ignorant of Him who from the Virgin is Emmanuel, they are deprived of His gift, which is eternal life; Romans 6:23 and not receiving the incorruptible Word, they remain in mortal flesh, and are debtors to death, not obtaining the antidote of life. To whom the Word says, mentioning His own gift of grace: "I said, You are all the sons of the Highest, and gods; but you shall die like men." He speaks undoubtedly these words to those who have not received the gift of adoption, but who despise the incarnation of the pure generation of the Word of God, defraud human nature of promotion into God, and prove themselves ungrateful to the Word of God, who became flesh for them. For it was for this end that the Word of God was made man, and He who was the Son of God became the Son of man, that man, having been taken into the Word, and receiving the adoption, might become the son of God. For by no other means could we have attained to incorruptibility and immortality, unless we had been united to incorruptibility and immortality. But how could we be joined to incorruptibility and immortality, unless, first, incorruptibility and immortality had become that which we also are, so that the corruptible might be swallowed up by incorruptibility, and the mortal by immortality, that we might receive the adoption of sons?

Against Heresies (Book III, Chapter 19)

2. For this reason [it is, said], Who shall declare His generation? Isaiah 53:8 since He is a man, and who shall recognise Him? Jeremiah 17:9 But he to whom the Father which is in heaven has revealed Him, Matthew 16:16 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, John 1:13 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. But that He had, beyond all others, in Himself that pre-eminent birth which is from the Most High Father, and also experienced that pre-eminent generation which is from the Virgin, Isaiah 7:14 the divine Scriptures do in both respects testify of Him: also, that He was a man without comeliness, and liable to suffering; Isaiah 53:2 that He sat upon the foal of an ass; Zechariah 9:9 that He received for drink, vinegar and gall; that He was despised among the people, and humbled Himself even to death and that He is the holy Lord, the Wonderful, the Counsellor, the Beautiful in appearance, and the Mighty God, Isaiah 9:6 coming on the clouds as the Judge of all men; Daniel 7:13 — all these things did the Scriptures prophesy of Him.

Against Heresies (Book III, Chapter 19)

3. For as He became man in order to undergo temptation, so also was He the Word that He might be glorified; the Word remaining quiescent, that He might be capable of being tempted, dishonoured, crucified, and of suffering death, but the human nature being swallowed up in it (the divine), when it conquered, and endured [without yielding], and performed acts of kindness, and rose again, and was received up [into heaven]. He therefore, the Son of God, our Lord, being the Word of the Father, and the Son of man, since He had a generation as to His human nature from Mary — who was descended from mankind, and who was herself a human being — was made the Son of man. Isaiah 7:13 Wherefore also the Lord Himself gave us a sign, in the depth below, and in the height above, which man did not ask for, because he never expected that a virgin could conceive, or that it was possible that one remaining a virgin could bring forth a son, and that what was thus born should be God with us, and descend to those things which are of the earth beneath, seeking the sheep which had perished, which was indeed His own peculiar handiwork, and ascend to the height above, offering and commending to His Father that human nature (hominem) which had been found, making in His own person the first-fruits of the resurrection of man; that, as the Head rose from the dead, so also the remaining part of the body — [namely, the body] of everyman who is found in life — when the time is fulfilled of that condemnation which existed by reason of disobedience, may arise, blended together and strengthened through means of joints and bands Ephesians 4:16 by the increase of God, each of the members having its own proper and fit position in the body. For there are many mansions in the Father’s house, John 14:2 inasmuch as there are also many members in the body.

Against Heresies (Book III, Chapter 19)

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 fullness of the times of the adoption had arrived, that the kingdom of heaven had drawn near, and that He was dwelling within those that believe in Him who was born Emmanuel of the Virgin. To this effect they testify, [saying,] that before Joseph had come together with Mary, while she therefore remained in virginity, she was found with child of the Holy Ghost; Matthew 1:18 and that the angel Gabriel said to her, The Holy Ghost shall come upon you, and the power of the Highest shall overshadow you; therefore also that holy thing which shall be born of you shall be called the Son of God; Luke 1:35 and that the angel said to Joseph in a dream, Now this was done, that it might be fulfilled which was spoken by Isaiah the prophet, Behold, a virgin shall be with child. Matthew 1:23 But the elders have thus interpreted what Esaias said: And the Lord, moreover, said to Ahaz, Ask for yourself a sign from the Lord your God out of the depth below, or from the height above. And Ahaz said, I will not ask, and I will not tempt the Lord. And he said, It is not a small thing for you to weary men; and how does the Lord weary them? Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son; and you shall call His name Emmanuel. Butter and honey shall He eat: before He knows or chooses out things that are evil, He shall exchange them for what is good; for before the child knows good or evil, He shall not consent to evil, that He may choose that which is good. Isaiah 7:10-17 Carefully, then, has the Holy Ghost pointed out, by what has been said, His birth from a virgin, and His essence, that He is God (for the name Emmanuel indicates this). And He shows that He is a man, when He says, Butter and honey shall He eat; and in that He terms Him a child also, [in saying,] before He knows good and evil; for these are all the tokens of a human infant. But that He will not consent to evil, that He may choose that which is good,— this is proper to God; that by the fact, that He shall eat butter and honey, we should not understand that He is a mere man only, nor, on the other hand, from the name Emmanuel, should suspect Him to be God without flesh. (Ibid., Chapter 21 A vindication of the prophecy in Isaiah (7:14) against the misinterpretations of Theodotion, Aquila, the Ebionites, and the Jews. Authority of the Septuagint version. Arguments in proof that Christ was born of a Virgin.)

Against Heresies (Book IV, Chapter 5)

2. For our Lord and Master, in the answer which He gave to the Sadducees, who say that there is no resurrection, and who do therefore dishonour God, and lower the credit of the law, did both indicate a resurrection, and reveal God, saying to them, You err, not knowing the Scriptures, nor the power of God. For, touching the resurrection of the dead, He says, have you not read that which was spoken by God, saying, I am the God of Abraham, the God of Isaac, and the God of Jacob? And He added, He is not the God of the dead, but of the living; for all live to Him. By these arguments He unquestionably made it clear, that He who spoke to Moses out of the bush, and declared Himself to be the God of the fathers, He is the God of the living. For who is the God of the living unless He who is God, and above whom there is no other God? Whom also Daniel the prophet, when Cyrus king of the Persians said to him, Why do you not worship Bel? did proclaim, saying, Because I do not worship idols made with hands, but the living God, who established the heaven and the earth and has dominion over all flesh. Again did he say, I will adore the Lord my God, because He is the living God. He, then, who was adored by the prophets as the living God, He is the God of the living; and His Word is He who also spoke to Moses, who also put the Sadducees to silence, who also bestowed the gift of resurrection, thus revealing [both] truths to those who are blind, that is, the resurrection and God [in His true character]. For if He be not the God of the dead, but of the living, yet was called the God of the fathers who were sleeping, they do indubitably live to God, and have not passed out of existence, since they are children of the resurrection. But our Lord is Himself the resurrection, as He does Himself declare, I am the resurrection and the life. John 11:25 But the fathers are His children; for it is said by the prophet: Instead of your fathers, your children have been made to you. Christ Himself, therefore, together with the Father, is the God of the living, who spoke to Moses, and who was also manifested to the fathers.

Against Heresies (Book IV, Chapter 6)

7. For it was fitting that the truth should receive testimony from all, and should become [a means of] judgment for the salvation indeed of those who believe, but for the condemnation of those who believe not; that all should be fairly judged, and that the faith in the Father and Son should be approved by all, that is, that it should be established by all [as the one means of salvation], receiving testimony from all, both from those belonging to it, since they are its friends, and by those having no connection with it, though they are its enemies. For that evidence is true, and cannot be gainsaid, which elicits even from its adversaries striking testimonies in its behalf; they being convinced with respect to the matter in hand by their own plain contemplation of it, and bearing testimony to it, as well as declaring it. But after a while they break forth into enmity, and become accusers [of what they had approved], and are desirous that their own testimony should not be [regarded as] true. He, therefore, who was known, was not a different being from Him who declared No man knows the Father, but one and the same, the Father making all things subject to Him; while He received testimony from all that He was very man, and that HE WAS VERY GOD, from the Father, from the Spirit, from angels, from the creation itself, from men, from apostate spirits and demons, from the enemy, and last of all, from death itself. But the Son, administering all things for the Father, works from the beginning even to the end, and without Him no man can attain the knowledge of God. For the Son is the knowledge of the Father; but the knowledge of the Son is in the Father, and has been revealed through the Son; and this was the reason why the Lord declared: No man knows the Son, but the Father; nor the Father, save the Son, and those to whomsoever the Son shall reveal [Him]. For shall reveal was said not with reference to the future alone, as if then [only] the Word had begun to manifest the Father when He was born of Mary, but it applies indifferently throughout all time. For the Son, being present with HIS OWN HANDIWORK from the beginning, reveals the Father to all; to whom He wills, and when He wills, and as the Father wills. Wherefore, then, in all things, and through all things, there is one God, the Father, and one Word, and one Son, and one Spirit, and one salvation to all who believe in Him.