Clement of Alexandria

As, then, those who have shaken off sleep forthwith become all awake within; or rather, as those who try to remove a film that is over the eyes, do not supply to them from without the light which they do not possess, but removing the obstacle from the eyes, leave the pupil free; thus also we who are baptized, having wiped off the sins which obscure the light of the Divine Spirit, have the eye of the spirit free, unimpeded, and full of light, by which alone we contemplate the Divine, the Holy Spirit flowing down to us from above. This is the eternal adjustment of the vision, which is able to see the eternal light, since like loves like; and that which is holy, loves that from which holiness proceeds, which has appropriately been termed light. "Once ye were darkness, now are ye light in the Lord." Hence I am of opinion man was called by the ancients φώς. But he has not yet received, say they, the perfect gift. I also assent to this; but he is in the light, and the darkness comprehendeth him not.