Christ could have become flesh without birth, but he didn’t

Pray, tell me, why the Spirit of God descended into a woman’s womb at all, if He did not do so for the purpose of partaking of flesh from the womb. For He could have become spiritual flesh without such a process,—much more simply, indeed, without the womb than in it. He had no reason for enclosing Himself within one, if He was to bear forth nothing from it. Not without reason, however, did He descend into a womb. Therefore He received (flesh) therefrom; else, if He received nothing therefrom, His descent into it would have been without a reason, especially if He meant to become flesh of that sort which was not derived from a womb, that is to say, a spiritual one.

Tertullian
On the Flesh of Christ
Chapter XIX

Christ is the Word, the Spirit and the Power of God

The expression is in the singular number, as referring to the Lord, “He was born of God.”  And very properly, because Christ is the Word of God, and with the Word the Spirit of God, and by the Spirit the Power of God, and whatsoever else appertains to God.

Tertullian
On the Flesh of Christ
Chapter XIX

Christ is born of the Virgin without a human father

In order, therefore, that He who was already the Son of God—of God the Father’s seed, that is to say, the Spirit—might also be the Son of man, He only wanted to assume flesh, of the flesh of man without the seed of a man; for the seed of a man was unnecessary for One who had the seed of God. As, then, before His birth of the virgin, He was able to have God for His Father without a human mother, so likewise, after He was born of the virgin, He was able to have a woman for His mother without a human father. He is thus man with God, in short, since He is man’s flesh with God’s Spirit—flesh (I say) without seed from man, Spirit with seed from God. For as much, then, as the dispensation of God’s purpose concerning His Son required that He should be born of a virgin, why should He not have received of the virgin the body which He bore from the virgin?

 

Tertullian
On the Flesh of Christ
Chapter XVIII

It was God who became man to save us, not an angel

There is, then, no longer but one God, but one Savior, if there be two to contrive salvation, and one of them in need of the other. But was it His object indeed to deliver man by an angel? Why, then, come down to do that which He was about to expedite with an angel’s help? If by an angel’s aid, why come Himself also? If He meant to do all by Himself, why have an angel too? He has been, it is true, called “the Angel of great counsel,” that is, a messenger, by a term expressive of official function, not of nature. For He had to announce to the world the mighty purpose of the Father, even that which ordained the restoration of man.  But He is not on this account to be regarded as an angel, as a Gabriel or a Michael. For the Lord of the Vineyard sends even His Son to the laborers to require fruit, as well as His servants.

…Forasmuch, however, as it has been declared concerning the Son Himself, “Thou hast made Him a little lower than the angels” how will it appear that He put on the nature of angels if He was made lower than the angels, having become man, with flesh and soul as the Son of man? As “the Spirit of God,” however, and “the Power of the Highest,” can He be regarded as lower than the angels,—He who is verily God, and the Son of God? Well, but as bearing human nature, He is so far made inferior to the angels; but as bearing angelic nature, He to the same degree loses that inferiority. This opinion will be very suitable for Ebion, who holds Jesus to be a mere man, and nothing more than a descendant of David, and not also the Son of God; although He is, to be sure, in one respect more glorious than the prophets, inasmuch as he declares that there was an angel in Him, just as there was in Zechariah. Only it was never said by Christ, “And the angel, which spake within me, said unto me.” Neither, indeed, was ever used by Christ that familiar phrase of all the prophets, “Thus saith the Lord.” For He was Himself the Lord, who openly spake by His own authority, prefacing His words with the formula, “Verily, verily, I say unto you.” What need is there of further argument? Hear what Isaiah says in emphatic words, “It was no angel, nor deputy, but the Lord Himself who saved them.”

Tertullian
On the Flesh of Christ
Chapter XIV

Christ also has a human soul

Christ, however, could not have appeared among men except as a man. Restore, therefore, to Christ, His faith; believe that He who willed to walk the earth as a man exhibited even a soul of a thoroughly human condition, not making it of flesh, but clothing it with flesh.

Tertullian
On the Flesh of Christ
Chapter XI

Christ’s flesh was identical to our own

…what is blood but red fluid? what is flesh but earth in an especial form? Consider the respective qualities,—of the muscles as clods; of the bones as stones; the mammillary glands as a kind of pebbles. Look upon the close junctions of the nerves as propagations of roots, and the branching courses of the veins as winding rivulets, and the down (which covers us) as moss, and the hair as grass, and the very treasures of marrow within our bones as ores of flesh. All these marks of the earthy origin were in Christ; and it is they which obscured Him as the Son of God, for He was looked on as man, for no other reason whatever than because He existed in the corporeal substance of a man.

Tertullian
On the Flesh of Christ
Chapter IX

Heretics use the Scriptures to try and deny that God was actually born of a woman

But whenever a dispute arises about the nativity, all who reject it as creating a presumption in favour of the reality of Christ’s flesh, wilfully deny that God Himself was born, on the ground that He asked, “Who is my mother, and who are my brethren?”

Tertullian
On the Flesh of Christ
Chapter VII

Angels can take on flesh but are not born

It is plain that the angels bore a flesh which was not naturally their own; their nature being of a spiritual substance, although in some sense peculiar to themselves, corporeal; and yet they could be transfigured into human shape, and for the time be able to appear and have intercourse with men. Since, therefore, it has not been told us whence they obtained their flesh, it remains for us not to doubt in our minds that a property of angelic power is this, to assume to themselves bodily shape out of no material substance.

Tertullian
On the Flesh of Christ
Chapter VI