Death is bad. Really, really bad. It's pretty much the worst thing that can happen to a person. If you've ever had someone close to you die, you know this.
I was raised in a Catholic family. While not the most pious bunch, I can safely say that most or all of my extended family believe in some form of Heaven. "She's in a better place," they said of my great aunt, Frida. "He's watching over you now," they said of my grandfather, Richard. "I know I'll see her again someday," my mother said of her mother, Mary, one of the most beautiful people I have ever known, or expect to know, as long as I live.
But when I, the only atheist in the whole church, broke down sobbing at my grandmother's funeral, I was not the only one. As I looked around me, I did not see people grieving for a loved one who had taken a long trip. When my relatives say these comforting things, all I can hear are the words they cannot bring themselves to say: "They are gone, and they are never coming back."
I do not believe in any kind of afterlife; when the respiratory system halts its vital operation, and brain tissue starts to degenerate due to loss of oxygen, that person has ceased to exist. They are gone, forever.
That's the sort of thought that drives people away from skepticism and into the arms of religion and mysticism. The sort of thought that terrifies me to my core.
How do I deal with that?
Cryonics is the practice of lowering the temperature of an organism such that all biological activity (including decay) is suspended.
There is a consensus among scientists that someday, a suspension of neural activity will not prove ultimately fatal, and technology will provide a method to revive a person from this state. Until then, cryonic suspension of a recently deceased human body will preserve it in stasis, as long as its temperature remains below a certain threshold.
Cryonics is actually a lot more affordable than you probably think it is. Cryopreservation can be as cheap as $28,000, and you don't have to pay this in cash - the usual way of paying for cryonics is to purchase a life insurance policy that pays out to your cryonics provider upon your death. A term life policy that pays out at least $28,000 (at my age, anyway) can be as cheap as a few bucks a month.
The two main cryonics companies (at least in the US) are Alcor and the Cryonics Institute. Alcor is considered the state-of-the-art, but they charge $70,000 for neuropreservation (just your brain) and $200,000 for full-body preservation. The CI charges $28,000-$35,000 as a base rate for full-body cryopreservation (they don't offer a neuro option). Their respective websites have lots of resources for you to peruse.
If you have more questions, the LessWrong forum and the cryonics subreddit will have people who have gone through the process of signing up.
If you still need to be persuaded, search for “You Only Live Twice”, a blog post by Eliezer Yudkowsky.
At any rate, I don't intend to let a little thing like temporary interruption of neural activity get in the way of my immortality, and neither should you.