An important feature in the daily ritual of the temples was the opening of the gates to allow the rising Sun to touch the cult image or the lighting of lamps when this was not possible. This opening or lighting symbolized the daily rebirth of the Sun and its triumph over the dark forces of chaos which sought to devour and destroy it during its nocturnal travels in the underworld, which we find expressed in this myth about Orpheus:

When he descended to the underworld to recover his wife, Orpheus saw things there and ceased to honor Dionysos, through whom he had gained glory. Instead, he considered Helios the greatest of the Gods, calling him Apollon. (Eratosthenes, Vat. Fragm. 24)

In the solar theology of Orphism, all the Gods were thought to derive their power from the Sun, as we see in Macrobius:

Orpheus here has called the Sun “Phanes” (φανερός), from its light and enlightening, for the Sun sees all and is seen by all. The name Dionysos is derived, as the soothsayer himself says, from the fact that the Sun wheels round in an orbit. Cleanthes writes that the name Dionysos is derived from the Greek verb meaning “to complete” (διανύσαι), because the Sun in its daily course from its rising to its setting, making the Day and the Night, completes the circuit of the heavens. For the physicists Dionysos is “the mind of Zeus” (Διὸς νοῦς), since they hold that the Sun is the mind of the universe, and Zeus is the universe. (Macrobius, Saturnalia 1.18.13-15)

Members of the Orphic sect believe that material mind is represented by Dionysos himself, who, born of a single parent, is divided into separate parts. In their sacred rites they portray him as being torn to pieces at the hands of angry Titans and arising again from his buried limbs alive  and sound, their reason being that nous or Mind, by offering its undivided substance to be divided, and again, by returning from its divided state to the indivisible, both fulfills its worldly functions and does not forsake its secret nature. (Macrobius, Commentarium in Somnium Scipionis 1.12.12)

And the much earlier Derveni Papyrus col. 13 and 16

He swallowed the phallus of […], who sprang from the aither first.

Since in his [i.e. Orpheus] whole poetry he speaks about facts enigmatically, one has to speak about each word in turn. Seeing that people consider that generation is dependent upon the genitalia, and that without genitals there is no becoming, he used this (word), likening the Sun to a phallus. For without the Sun the things that are could not have become such … things that are … the Sun everything ….

It has been made clear above [that] he called the Sun a phallus. Since the beings that are now came to be from the already subsistent he says:

[with?] the phallus of the first-born king, onto which all the immortals grew (or: clung fast), blessed Gods and Goddesses And rivers and lovely springs and everything else That had been born then; and he himself became solitary

In these verses he indicates that the beings always subsisted, and the beings that are now came to be from (or: out of) subsisting things. And as to (the phrase): ‘and he himself became solitary’, by saying this, he makes clear that the Mind [Nous] itself, being alone, is worth everything, as if the others were nothing. For it would not be possible for the subsisting things to be such without the Mind. And in the following verse after this he said that Mind is worth everything:

Now he is king of all and will always be

…. Mind and …

So this triumph of the Sun was viewed as a triumph of all the Gods collectively. Even when the deities were not specifically solar in nature, it was still thought necessary for the rays of the Sun to alight upon the cult image in order to reenergize it. 

As far back as Homer we are told that the Greek deities reside in a brilliant heavenly abode – Olympos meaning “brightly shining” and their epiphany was often described with terms signifying the appearance of light or gold (Plato Phaedrus 250; Aristides Sacred Discourses 3; Plutarch On the Soul) – even the more chthonic deities such as Hekate who nevertheless bore the epithet Phosphoros or “light-bringer.”  

As you light your candle or lamp, meditate on these associations. Feel the triumph of light over darkness and what this meant to a world with no electricity, in which the dark was all-consuming and terrifying. Feel the heat and radiance as a herald to the shortly coming full divine presence. Think about the warmth and joy you feel on a sunny summer day, the flush of love in your cheeks, the conviviality of the hearth flame, how fire makes civilization possible – and how all of these are a blessing from the Gods. See the light as a beacon rising from your shrine up over your city, your country, the world, shining across the vast expanse of space, that the Gods and Spirits might be able to follow it back from their heavenly abode to your humble shrine.