In Ovid's Metamorphoses, we read story after story of a human (or demi-human) encountering the gods and being literally transformed by the experience. The stories generally come in one of two flavors: the human is ready for the experience and transcends his or her mortal bonds, or isn't ready... and is destroyed by the transformation. You can see the same pattern in stories told around the world and across the ages. Though we don't always recognize them as such, we still tell those stories.
I've been thinking about this recently, because I've just finished editing a book about Arthurian romances — stories that feature knights and ladies bashing up against divine forces and either rising to their challenge or being destroyed by them.
It's easy to see the stories of the Holy Grail as picking up Ovid's themes: they are explicitly stories about heroes' quests for apotheosis — about human knights like Galahad and Parzival struggling to and ultimately succeeding in coming face to face with transcendent power. These stories differ: the Galahad quests are explicitly Christian, while Parzival's is humanistic. Nonetheless, each is the tale of a mortal meeting the divine and surviving.
The romances that we'd sooner recognize as romances usually tell the other kind of story: the terrible, beautiful story of Tristan and Isolt is about a young couple who drink a magic love potion and are consumed by it. And yet it's interesting to wonder whether this couple — like Romeo and Juliet — would have chosen not to have their lives destroyed, if the price were to give up their love.
There's a reason that the ancients identified Love as a powerful god — Plato claimed that Eros was the eldest of the Olympians. We like to see love as a positive, comforting force. Yet in order to understand it, we have to embrace the idea that, like all transcendent forces, the flame of Love can be as destructive as it is empowering.
The Sufi poet al-Hallaj expresses an image that unites the two experiences. He said that the mystic (like the lover) approaches his divine Beloved like a moth to the flame. He knows that the experience will destroy him, but it will unite him with his love: "The light of the flame is the knowledge of reality, its heat is the reality of reality, and Union with it is the Truth of the reality." (The Tawasin of Mansur al-Hallaj) He is echoing Tristan's declaration (or rather, Tristan is echoing al-Hallaj): "What the death of which you tell is to be, I do not know; but this death suits me well. And if delightful Isolt is to go on being my death this way, then I shall gladly court an eternal death." (Tristan & Isolt, lines 12463-12502).