The manifestation of a god, that's what the Greek word means. It also means the sudden realization of a great truth. It seems to me that the two would pretty much go together.
In the Western church, that manifestation is celebrated with the story of three wise men (or magi, or kings. Important folks!) from a different country and tribe, making a long and perilous journey to see the manifestation of the Divine.
Now, we don't often hop up on the nearest camel to follow a star, but that longing for the divine is deep-seated. My favorite description of an epiphany lies in Kenneth Grahame's classic book, The Wind in the Willows, in the chapter called "The Piper at the gates of Dawn".
Rat and Mole have been all night on the river in their boat, searching for a lost baby otter. Rat hears snatches of a music so entrancing that he is compelled to follow the sound to its source. Just before dawn, they land their boat, and walk into a wood to …
…a little lawn of a marvellous green, set round with Nature's own orchard-trees – crab-apple, wild cherry, and sloe.
'This is the place of my song-dream, the place the music played to me,' whispered the Rat, as if in a trance. 'Here, in this holy place, here if anywhere, surely we shall find Him.'
Then suddenly Mole felt a great Awe fall upon him, an awe that turned his muscles to water, bowed his head, and rooted his feet to the ground. It was no panic terror – indeed he felt wonderfully at peace and happy – but it was an awe that smote and held him and, without seeing, he knew it could only mean that some august Presence was very, very near. With difficulty he turned to look for his friend, and saw him at his side cowed, stricken, and trembling violently. And still there was silence in the populous bird-haunted branches around them; and still the light grew and grew.
Perhaps he would never had dared to raise his eyes, but that, though the piping was now hushed, the call and the summons seemed still dominant and imperious. He might not refuse, were Death himself waiting to strike him instantly, once he had looked with mortal eye on things rightly kept hidden. Trembling he obeyed, and raised his humble head; and then, in that utter clearness of the immanent dawn, while Nature, flushed with fulness of incredible colour, seemed to hold her breath for the event, he looked into the very eyes of the Friend and Helper; saw the backward sweep of the curved horns, gleaming in the growing daylight; saw the sterm, hooked nose between the kindly eyes that were looking down on them humourously, while the bearded mouth broke into a half-smile at the corners; saw the rippling muscles on the arm that lay across the broad chest, the long supple hand still holding the pan-pipes only just fallen away from the parted lips; saw the splendid curves of the shaggy limbs disposed in majestic ease ont eh sward; saw, last of all, nestling between his very hooves, sleeping soundly in utter peace and contentment, the little, round, podgy, childish form of the baby otter. All this he saw, for one moment breathless and intense, vivid on the morning sky; and still, as he looked, he lived; and still, as he lived, he wondered.
'Rat!' he found breath to whisper, shaking. 'Are you afraid?'
'Afraid?' murmured the Rat, his eyes shining with unutterable love. 'Afraid! Of Him? O, never, never. And yet – and yet – O, Mole, I am afraid!'
Then the two animals, crouching to the earth, bowed their heads and did worship.
Sudden and magnificent, the sun's broad golden rim showed itself over the horizon facing them; and the first rays, shooting across the level water-meadows, took the animals full in the eyes and dazzled them. When they were able to look once more, the Vision had vanished, and the air was full of the carol of birds that hailed the dawn.
Rat and Mole are then caressed by a breeze that carries a gift of forgetfulness. It is not easy to see a god and carry on in every-day life. So they forget what happened, and gather up the sleeping otter. But they are left with the sense that Something happened.
That's us, too. Even after a great revelation, sometimes all we know is that Something happened. Perhaps everyone has this experience. I know from reading that saints do, and I know from life that artists do. It's in the vision we pursue, it's in the song we seek. We don't all call it by the same name, but that there is Something we have no doubt, and to tell about it is our calling.