I've frequently used literature to make sense of or mark significant moments during my life.
As I noted below, my wife and I included a passage of poetry from Milton on our wedding invitations:
The world was all before them, where to choose
Their place of rest, and providence their guide.
They, hand in hand, with wand'ring steps and slow
Through Eden took their solitary way.
The hope and humanity in these lines helped make the moment more meaningful.
My son's birth was the most intense moment of my life. And when I finally held him in my hands, I quoted King Lear to him: "When we are born, we cry that we are come to this great stage of fools." At this moment, this intense, dramatic, meaningful moment, I called on the Bard for deeper meaning.
During one stretch of bad luck (it seems insignificant now, but during the frugal days of grad school, it felt rather overwhelming), I was rather consumed by the idea that the universe was just a mishmash of hazard and chance, entirely indifferent to us all. I taped to my door two passages: one from the Bible, when Jesus tells his disciples not to worry so much (As an Obsessive Complusive, this is a pretty meaningful passage for me. Indeed, I again put the passage on my wall at my current house, feeling I need to be reminded that I ought not worry). But I also put a passage on the door from Hemingway's Farewell to Arms, a passage exploring the indifference of the cosmos to human problems. That I could look at these two passages every day in some way helped me.
Literature has not been an abstract, dry study in my life. These are rather concrete examples when I've used literature in my own life. In a broader sense, I've seen the world differently, I've experienced human beings differently, because I've read Dostoevsky, because I've read Fowles, because I've read Sartre. I see the world, myself, and humanity in a different way because of what I've read.
And literature offers us metaphors to make sense of our existence. Homer gave us Scylla and Charybdis to articulate the difficult, impossible choices we sometimes confront in our lives. In the shadow of Abu Ghraib, Cornwall's servant in King Lear, who disobeys his master to try stop him from blinding Gloucester, has deep resonance. Wilfred Owen gives us a poetry to discuss the horrors of war; we can share the reference of "Dulce et Decorum Est." The Lord of the Flies offers us an image: if we want to consider the dark side of humanity, we can picture a bunch of murderous boys running around an island (but then, that's not necessary: when I consider the dark side of humanity, I picture black and white images of Nazis and Death Camps, recalling the Holocaust literature I've read that made me ache for the evils of humankind).
Literature can be a deeply meaningful experience for our lives. It can help us understand ourselves and the world we face; it can help us confront the universal reality of death. Part of that is the aesthetic: when poetry renders an idea into a new, beautiful, resonant form, it has powerfully connected with us. But that aesthetic meaning can be richer when it helps us to consider the experience, the thought, the meaning within it (Lutheran theology might be used to explain the relationship between content and form. Literature is like Consubstantiation: as Lutherans understand communion to be both bread and flesh, wine and blood, so is great literature both content and form, not meaningfully separated). Ultimately, literature has little to no meaning other than that which the reader is willing to give it. But if we willingly engage in it, it can provide us with something deep and meaningful.
I don't engage literature as an academic exercise. I engage literature as a personal renewal, as a spiritual growth, as a meaningful understanding of myself in the cosmos.