12 And what does this faith effect at present? What does it by so many testimonies of Scripture, by its manifold lessons, its various and plentiful exhortations, but make us “see now through a glass darkly, and hereafter face to face.” But return not now in thought again to this your bodily face. Think only of the face of the heart. Force, compel, press your heart to think of things divine. Whatsoever occurs to your mind that is like to a body, throw it off from you.
If you can not yet say, “It is this,” yet at least say, “It is not this.” For when will you be able to say, “This is God”? Not even then, when you shall see Him; for what you shall then see is ineffable. Thus the Apostle says, that he “was caught up into the third heaven, and heard ineffable words.” If the words are ineffable, what is He whose words they are? Therefore as you think of God, perchance there is presented to you the idea of some human figure of marvellous and exceeding greatness, and you have set it before the eyesof your mind as something very great, and grand, and of vast extension.
Still somewhere you have set bounds to it. If you have, it is not God. But if you have not set bounds to it, where can the face be? You are fancying to yourself some huge body, and in order to distinguish the members in it, you must needs set bounds to it. For in no other way but by setting bounds to this large body, can you distinguish the members. But what are you about, O foolish and carnal imagination! You have made a large bulky body, and so much the larger, as you have thought the more to honour God. Another adds one cubit to it, and makes it greater than before.
Source: Sermons on Selected Lessons of the New Testament (New Advent)