The same command that once broke open the first morning still works in the dark of a person, striking light where there had only been shadow. The heart dulled by despair, sure its inside is a closed and lightless place, has forgotten who speaks to darkness. A mirror gone grey is not thrown out; it is polished until it can hold a face again.
So a person turns toward that light on purpose, in prayer or a moment of stillness, and lets it do the work no scrubbing of his own could manage. Where the glory becomes knowable, in a single human face, the Giver of light is already present, shining out rather than staying hidden.