But I've also thought about how living forever and knowing everything might take the meaning out of a vital existence.
So here's the real deal:
Example One:
You suddenly have a car accident and see that you are gushing blood from your leg where broken bone is sticking through.
Do you call 911 on your cell phone or skip it since sooner or later you might discover that life loses meaning because you learned too much?
Example Two:
You are 85 years old and are in a car wreck exactly the same. You are still you. Do you call 911 or do you skip it because you decide "your time has come" (whatever the hell
that means!)?
Example Three:
You have a heart attack tomorrow evening. The surgeons tell you that if you are going to survive you will have to accept a heart transplant but this will mean you will need to take immune suppressant medications for the rest of your life to prevent your body from rejecting your new heart.
Do you agree to the heart transplant or do you decide that having to take meds for years to come is too much bother so you choose to die?
Example Four:
Same as above with a bad heart but the surgeon asks you if you would accept a heart that they will grow in the lab from your adult stem cells, which will take about ten weeks (
http://www.youtube.com/watch?v=j9hEFUpTVPA).
There will be zero rejection of your new heart because it is your own tissue.
Do you agree to the procedure or do you skip it and choose to die because in some future yet to come you might become bored?
Example Five:
You are 95 years old and feel lousy. Your eyesight is bad, your hearing is bad, you can hardly walk - you are in terrible shape.
Your doctor asks you if you would like to have a series of injections that will reverse the aging of your body so that you will grow younger"? (See Aubrey de Grey's SENS project).
Do you take the treatment and allow your infirm body and brain to grow younger or you do you skip it and "let nature take it's course"?
Example Six:
Your body is maintained at a physical age of about thirty through various medical repair injection treatments as well as swarms of nanobots that swim through your bloodstream. Unless you get hit by a bus or get blown sky high by some terrorist attack, you can expect that your physical machine including your brain can be maintained indefinitely.
(The IRS loves you because you will also keep paying taxes indefinitely.

).
You have also been taking advantage of brain scan backups to save your memories "just in case". (This technology has been around since about 2040, ten years after the first computer would equal the computing power of the human brain, enabling the effective back-engineering of the brain).
You are hit on a sunny afternoon by a meteor and your body is vaporized. You wake up in a hospital bed and are informed by the doctor there that you are actually a clone of the original "you" who was killed by the meteor and your memories of your former life were uploaded into your cloned brain.
You feel just like yourself. You remember everything about your life (including how the IRS loves you). You find it very hard to believe that a former "version" of you was killed.
Do you thank the doctor for restoring you to health or do you choose to erase your back-up memories and blow your brains out because your new existence is an affront to God?
Example Seven:
Same meteor, same accident but this time when you wake up the doctor explains that you are not in the real world. Instead, your brain scan backup was used to create "you" in this simulation of the real world, a virtual reality (such as was portrayed in the film "The Matrix").
You still feel exactly the same. You feel like you are yourself. You seem to be able to remember your past just fine.
Do you thank the doctor for saving your life or do you demand that they pull the plug on this simulation of life because you only want to live in the real world, not one that is indistinguishable from the real world?
-------------------
I will stop here since you are only discussing longevity and not really what happens as human beings have the option to become incrementally smarter and stronger. (Clark Kent, move over!).
All of the above issues are simply choices between life and death.
If "survival is the highest law" for the Satanist, then these questions will answer themselves as they come into play.
I have no doubt there will be groups who will reject such schemes when they come into existence, just as there are religions that still reject blood transfusions.
However, most people will continue to follow the instinct for survival and choose life over death.
To me, it is a no-brainer.
Something is better than nothing.
Some chance is always better than no chance.
Just my opinion.