As long as we keep living we are bound to keep discovering new things that we cant comprehend with only 100 years fun and interesting things are always created by our creativity and imagination without those 2 important you can see why some people want to have an end while those that possess those traits often would like to keep living and learning so much more about the universe and having fun around great family friends that they would most likely take living forever as a blessing to forever enjoy what our Universe has to offer and thats my belief and opinion on why immortality is a reasonable goal for humans and everyone to achieve so many possibilities and fun and exciting things many cant live long enough to enjoy.
It is every living creature's most basic instinct to survive. If we figure out a way to live forever, we will take it. This is why so many people flock to life after death. This is why we have doctors. This is why we pull our hands away from something hot. This is why even the most basic life form reproduces. The question is really how will we attain this goal.
Immortality is a reasonable goal for humans. Our souls are immortal in Christianity and this is a major belief system in the world. There is no real evidence to the contrary that our souls do not go to heaven. I think immortality is already in existence. If we want it we need to act in ways that God wants us to.
The reason immortality is a reasonable goal is because we have been, decade after decade, addings years to our life spans as human beings. And of late, they have been able to regrow organs from stem-cells, reverse the aging in mice, and give people robotic implants that work better than the original organ. It's only a matter of time.
No, the human body is not constructed in a way that immortality is achievable. Every part of the human body would eventually have to be replaced, from the eyeballs to the vital organs, because the parts degenerate over time. Eventually, the person would become a shell, housing a smattering of replaced parts from various sources. If the person has none of the original parts, that person no longer exists.
Given that humans are completely unaware of what happens after death, I certainly do not want to be immortal and potentially miss the chance at something better after this life. Secondly, I do not believe immortality is a reasonable goal for humans. The body deteriorates and we have no way to survive past the life of our body, that we are aware of.
People do not think about immortality except during church services on Sunday. The rest of the week, their thoughts are far from it. I seriously doubt that anyone pauses before they make a decision to consider the effect it might have on their chances for immortality. When organized religion was stronger immortality may have been a reasonable goal, but it is no longer.