Something I run into occasionally is people comparing the idea of healthy life extension to the idea of faith in an afterlife, or similarly, making the assumption that anyone interested in superlongevity believes that it is somehow a "given".
Well, superlongevity is not a given. It certainly won't be for a long, long time, if ever, since each time someone crosses a new "upper limit" of human age, new challenges at keeping that person alive are going to present themselves. And remember that aging is only one challenge sentient beings face; surely in the future there will be new and unanticipated threats to sustaining our lives, but for now, age-related death is an immediate concern for so many that it can scarcely be ignored. Supporting longevity research is a way of addressing this concern, and this sort of support has nothing to do with blind faith.
Blind faith in longevity science coming to "rescue" you is just as silly as blind faith in the notion of pink rabbits coming to make you breakfast tomorrow morning. Supporting longevity research is acknowledging that there is nothing special about aging that makes it any less solvable than any other complex engineering problem -- it's not a mystical force or a cosmic directive, it's a biological process. And the means of counteracting this process won't be mystical forces either -- they'll be the result of a lot of hard work and scientific inquiry.
Most modern articles are written with the daily-paper reader in mind: someone who skims articles, notices one or two things that make him go, "Hmm, wow, I didn't know that!", before going off to watch the latest nighttime drama. It is essential that anyone who takes life extension seriously learn to read scientific literature and develop good critical thinking skills.
Get familiar with common logical fallacies and cognitive biases. This is not only good for the brain and reasoning faculties, but a lot of fun. One thing I've always done as an excercise in this regard is make a point to listen to, and read, viewpoints I know I am not inclined to agree with. Things like that can help guard against confirmation bias, which nobody who seriously wants to see healthy life extension pan out can afford. There's a lot of quackery out there, and a lot of products being advertised as "anti-aging" with no supporting data and no real long-term verifiable promises.
But, some might say, isn't all longevity science therefore quackery, since its claims have not yet been verified? Of course not. There is a difference between making a positive claim (as a quack would) and presenting an hypothesis (as a scientist studying mitochondrial DNA might). Nobody doing real longevity science is currently saying that what they're doing is definitely going to do exactly what we want it to. Rather, they're looking at the available data and trying to see what can be extrapolated from that data, whether toward the development of interventions or the design of further experiments.
"Intelligent Design" advocates often claim that since science doesn't deal in absolutes, it doesn't work as a foundation for interpreting reality. But people who make that sort of statement are ignoring the fact that it is the process of science which serves as the foundation, not the claims science might make at any given time!
There's nothing absolute about the scientific method. Reason wrote recently about the iterative nature of scientific progress: that is, failures and setbacks are part of the package. Negative data is still data, after all, and every time we learn more about what doesn't work, this information can help us move toward finding something that does.
There's a big difference between believing something will happen because it makes you feel better to do so, and having a goal in mind, not knowing whether it's possible or not, but being motivated to work to see if it is possible. Life extension science falls into the latter category for me. It isn't a fantasy or a daydream or an existential palliative. It's an experiment, and a project, and something well worth exploring. Whatever we can learn about anatomy and health represents data for the scientific memepool, which can translate to the potential for better lives for everyone, now and in the future.