The ancient mystery of the "sun at midnight," symbolizes the spiritual light that lies hidden within the dark. The Celts knew that light emerges out of darkness and so their days began at dusk, as if the sun was seeded in the black earth of night.
I said to the one who stood at the Gate of the Year,
Give me a light that I might go safely out into the darkness.
The gatekeeper replied,
Go out into the darkness and put your hand
into the hand of God.
That shall be more to you than a light and safer than a known way.