386–429 · Augustine of Hippo, Letters 92.4
Moreover, when you read, “Now we see through a glass darkly, but then face to face,” learn from this that we shall then see Him face to face by the same means by which we now see Him through a glass darkly. In both cases alike, the vision of God belongs to the inner man, whether when we walk in this pilgrimage still by faith, in which it uses the glass and the αἴνιγμα, or when, in the country which is our home, we shall perceive by sight, which vision the words “face to face” denote. Let the flesh raving with carnal imaginations hear these words: “God is a Spirit, and they that worship Him must worship Him in spirit and in truth.” If this be the manner of worshipping Him, how much more of seeing Him! For who durst affirm that the Divine essence is seen in a corporal manner, when He has not permitted it to be worshipped in a corporal manner?