5 But you are not able to conceive of any such thing. Such ignorance is more pious than presumptuous knowledge. For we are speaking of God. It is said, “And the Word was God.” We are speaking of God; what marvel, if you do not comprehend? For if you comprehend, He is not God. Be there a pious confession of ignorance, rather than a rash profession of knowledge. To reach to God in any measure by the mind, is a great blessedness; but to comprehend Him, is altogether impossible.
God is an object for the mind, He is to be understood; a body is for the eyes, it is to be seen. But do you think that you comprehend a body by the eye? You can not at all. For whatever you look at, you do not see the whole. If you see a man's face, you do not see his back at the time you see the face; and when you see the back, you do not at that time see the face. Thou dost not then so see, as to comprehend; but when you see another part which you had not seen before, unless memory aid you to remember that you have seen that from which you withdraw, you could never say that you had comprehended anything even on the surface.
Thou handlest what you see, turnest it about on this side and that, or yourself dost go round it to see the whole. In one view then you can not see the whole. And as long as you turn it about to see it, you are but seeing the parts; and by putting together that you have seen the other parts, you fancy that you see the whole. But this must not be understood as the sight of the eyes, but the activity of the memory. What then can be said, Brethren, of that Word? Lo, of the bodies which are before our eyes we say they cannot comprehend them by a glance; what eye of the heart then comprehends God?
Enough that it reach to Him if the eye be pure. But if it reach, it reaches by a sort of incorporeal and spiritual touch, yet it does not comprehend; and that, only if it be pure. And a man is made blessed by touching with the heart That which ever abides Blessed; and that is this Very Everlasting Blessedness, and that Everlasting Life, whereby man is made to live; that Perfect Wisdom, whereby man is made wise; that Everlasting Light, whereby man becomes enlightened. And see how by this touch you are made what you were not, you do not make that you touch be what it was not before.
I repeat it, there grows no increase to God from them that know Him, but to them that know Him, from the knowledge of God. Let us not suppose, dearly beloved Brethren, that we confer any benefit on God, because I have said that we give Him in a manner a price. For we do not give Him anything whereby He can be increased, Who when you fall away, is Entire, and when you return, abides Entire, ready to make Himself seen that He may bless those who turn to Him, and punish those with blindness who turn away. For by this blindness, as the beginning of punishment, does He first execute vengeance on the soul that turns away from Him. For whoso turns away from the True Light, that is from God, is at once made blind. He is not yet sensible of his punishment, but he has it already.
Source: Sermons on Selected Lessons of the New Testament (New Advent)