1 And now let us explain the cause for which the incorporeal Word of God assumed this mortal body as a medium of intercourse with man. How, indeed, else than in human form could that Divine and impalpable, that immaterial and invisible Essence manifest itself to those who sought for God in created and earthly objects, unable or unwilling otherwise to discern the Author and Maker of all things?
2. As a fitting means, therefore, of communication with mankind, he assumed a mortal body, as that with which they were themselves familiar; for like, it is proverbially said, loves its like. To those, then, whose affections were engaged by visible objects, who looked for gods in statues and lifeless images, who imagined the Deity to consist in material and corporeal substance, nay, who conferred on men the title of divinity, the Word of God presented himself in this form.
3. Hence he procured for himself this body as a thrice-hallowed temple, a sensible habitation of an intellectual power; a noble and most holy form, of far higher worth than any lifeless statue. The material and senseless image, fashioned by base mechanic hands, of brass or iron, of gold or ivory, wood or stone, may be a fitting abode for evil spirits: but that Divine form, wrought by the power of heavenly wisdom, was possessed of life and spiritual being; a form animated by every excellence, the dwelling-place of the Word of God, a holy temple of the holy God.
4. Thus the indwelling Word conversed with and was known to men, as kindred with themselves; yet yielded not to passions such as theirs, nor owned, as the natural soul, subjection to the body. He parted not with anything of his intrinsic greatness, nor changed his proper Deity. For as the all-pervading radiance of the sun receives no stain from contact with dead and impure bodies; much less can the incorporeal power of the Word of God be injured in its essential purity, or part with any of its greatness, from spiritual contact with a human body.
5. Thus, I say, did our common Saviour prove himself the benefactor and preserver of all, displaying his wisdom through the instrumentality of his human nature, even as a musician uses the lyre to evince his skill. The Grecian myth tells us that Orpheus had power to charm ferocious beasts, and tame their savage spirit, by striking the chords of his instrument with a master hand: and this story is celebrated by the Greeks, and generally believed, that an unconscious instrument could subdue the untamed brute, and draw the trees from their places, in obedience to its melodious power. But he who is the author of perfect harmony, the all-wise Word of God, desiring to apply every remedy to the manifold diseases of the souls of men, employed that human nature which is the workmanship of his own wisdom, as an instrument by the melodious strains of which he soothed, not indeed the brute creation, but savages endued with reason; healing each furious temper, each fierce and angry passion of the soul, both in civilized and barbarous nations, by the remedial power of his Divine doctrine. Like a physician of perfect skill, he met the diseases of their souls who sought for God in nature and in bodies, by a fitting and kindred remedy, and showed them God in human form.
6. And then, with no less care for the body than the soul, he presented before the eyes of men wonders and signs, as proofs of his Divine power, at the same time instilling into their ears of flesh the doctrines which he himself uttered with a corporeal tongue. In short, he performed all his works through the medium of that body which he had assumed for the sake of those who else were incapable of apprehending his Divine nature.
7. In all this he was the servant of his Father's will, himself remaining still the same as when with the Father; unchanged in essence, unimpaired in nature, unfettered by the trammels of mortal flesh, nor hindered by his abode in a human body from being elsewhere present.
8. Nay, at the very time of his intercourse with men, he was pervading all things, was with and in the Father, and even then was caring for all things both in heaven and earth. Nor was he precluded, as we are, from being present everywhere, or from the continued exercise of his Divine power. He gave of his own to man, but received nothing in return: he imparted of his Divine power to mortality, but derived no accession from mortality itself.
9. Hence his human birth to him brought no defilement; nor could his impassible Essence suffer at the dissolution of his mortal body. For let us suppose a lyre to receive an accidental injury, or its chord to be broken; it does not follow that the performer on it suffers: nor, if a wise man's body undergo punishment, can we fairly assert that his wisdom, or the soul within him, are maimed or burned.
10. Far less can we affirm that the inherent power of the Word sustained any detriment from his bodily passion, any more than, as in the instance we have already used, the solar rays which are shot from heaven to earth contract defilement, though in contact with mire and pollution of every kind. We may, indeed, assert that these things partake of the radiance of the light, but not that the light is contaminated, or the sun defiled, by this contact with other bodies.
11. And indeed these things are themselves not contrary to nature; but the Saviour, the incorporeal Word of God, being Life and spiritual Light itself, whatever he touches with Divine and incorporeal power must of necessity become endued with the intelligence of light and life. Thus, if he touch a body, it becomes enlightened and sanctified, is at once delivered from all disease, infirmity, and suffering, and that which before was lacking is supplied by a portion of his fullness.
12. And such was the tenor of his life on earth; now proving the sympathies of his human nature with our own, and now revealing himself as the Word of God: wondrous and mighty in his works as God; foretelling the events of the far distant future; declaring in every act, by signs, and wonders, and supernatural powers, that Word whose presence was so little known; and finally, by his Divine teaching, inviting the souls of men to prepare for those mansions which are above the heavens.
Source: Oration in Praise of Constantine (New Advent)