“Harry Dresden: Because Thomas is too pretty to die. And because I'm too stubborn to die. And most of all because tomorrow is Oktoberfest, Butters, and polka will never die.”

Source: Dead Beat

"Tomorrow" (1919), as translated in A Soviet Heretic : Essays by Yevgeny Zamyatin (1970) edited and translated by Mirra Ginsburg
Context: Every today is at the same time both a cradle and a shroud: a shroud for yesterday, a cradle for tomorrow. Today, yesterday, and tomorrow are equally near to one another, and equally far. They are generations, they are grandfathers, fathers, and grandsons. And grandsons invariably love and hate the fathers; the fathers invariably hate and love the grandfathers.
Today is doomed to die — because yesterday died, and because tomorrow will be born. Such is the wise and cruel law. Cruel, because it condemns to eternal dissatisfaction those who already today see the distant peaks of tomorrow; wise, because eternal dissatisfaction is the only pledge of eternal movement forward, eternal creation. He who has found his ideal today is, like Lot's wife, already turned to a pillar of salt, has already sunk into the earth and does not move ahead. The world is kept alive only by heretics: the heretic Christ, the heretic Copernicus, the heretic Tolstoy. Our symbol of faith is heresy: tomorrow is an inevitable heresy of today, which has turned into a pillar of salt, and to yesterday, which has scattered to dust. Today denies yesterday, but is a denial of denial tomorrow. This is the constant dialectic path which in a grandiose parabola sweeps the world into infinity. Yesterday, the thesis; today, the antithesis, and tomorrow, the synthesis.

Source: The Subtle Art of Not Giving a F*ck (2016), Chapter 9, “...And Then You Die” (p. 208)

Dawkins has stated on many occasions that this passage will be read at his funeral.
Unweaving the Rainbow (1998)
Context: We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who will in fact never see the light of day outnumber the sand grains of Sahara. Certainly those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively outnumbers the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here. We privileged few, who won the lottery of birth against all odds, how dare we whine at our inevitable return to that prior state from which the vast majority have never stirred?

In the loneliness of my life, my father dead, my brother dead, my mother far away, my sister and my wife far away, nothing here but my own tragic hands that once were guarded by a world, a sweet attention, that now are left to guide and disappear their own way into the common dark of all our death, sleeping in me raw bed, alone and stupid...
Visions of Cody (1960)

Johnny Got His Gun (1938)
Context: Just say "mister I'm sorry, I got no time to die, I'm too busy" and then turn and run like hell. If they say coward why don't pay any attention because it's your job to live not to die. If they talk about dying for principles that are bigger than life, you say "mister you're a liar. Nothing is bigger than life". There's nothing noble in death. What's noble about lying in the ground and rotting? What's noble about never seeing the sunshine again? What's noble about having your legs and arms blown off? What's noble about being an idiot? What's noble about being blind and deaf and dumb? What's noble about being dead? Because when you're dead, mister, it's all over. It's the end. You're less than a dog, less than a rat, less than a bee or an ant, less than a white maggot crawling around on a dungheap. You're dead, mister, and you died for nothing.

Source: Invincible

Source: Stormbreaker

Source: The Name of the Star