Christ could not be described as being man without flesh, nor the Son of man without any human parent; just as He is not God without the Spirit of God, nor the Son of God without having God for His father. Thus the nature of the two substances displayed Him as man and God,—in one respect born, in the other unborn; in one respect fleshly, in the other spiritual; in one sense weak, in the other exceeding strong; in one sense dying, in the other living. This property of the two states—the divine and the human—is distinctly asserted with equal truth of both natures alike, with the same belief both in respect of the Spirit and of the flesh. The powers of the Spirit, proved Him to be God, His sufferings attested the flesh of man.
Tertullian
On the Flesh of Christ
Chapter V