City of God

It is a great and very rare thing for a man, after he has contemplated the whole creation, corporeal and incorporeal, and has discerned its mutability, to pass beyond it, and, by the continued soaring of his mind, to attain to the unchangeable substance of God, and, in that height of contemplation, to learn from God Himself that none but He has made all that is not of the divine essence. For God speaks with a man not by means of some audible creature dinning in his ears, so that atmospheric vibrations connect Him that makes with him that hears the sound, nor even by means of a spiritual being with the semblance of a body, such as we see in dreams or similar states; for even in this case He speaks as if to the ears of the body, because it is by means of the semblance of a body He speaks, and with the appearance of a real interval of space—for visions are exact representations of bodily objects.

Not by these, then, does God speak, but by the truth itself, if any one is prepared to hear with the mind rather than with the body. For He speaks to that part of man which is better than all else that is in him, and than which God Himself alone is better. For since man is most properly understood (or, if that cannot be, then, at least, believed) to be made in God's image, no doubt it is that part of him by which he rises above those lower parts he has in common with the beasts, which brings him nearer to the Supreme.

But since the mind itself, though naturally capable of reason and intelligence is disabled by besotting and inveterate vices not merely from delighting and abiding in, but even from tolerating His unchangeable light, until it has been gradually healed, and renewed, and made capable of such felicity, it had, in the first place, to be impregnated with faith, and so purified. And that in this faith it might advance the more confidently towards the truth, the truth itself, God, God's Son, assuming humanity without destroying His divinity, established and founded this faith, that there might be a way for man to man's God through a God-man.

For this is the Mediator between God and men, the man Christ Jesus. For it is as man that He is the Mediator and the Way. Since, if the way lies between him who goes, and the place whither he goes, there is hope of his reaching it; but if there be no way, or if he know not where it is, what boots it to know whither he should go? Now the only way that is infallibly secured against all mistakes, is when the very same person is at once God and man, God our end, man our way.