Well, I guess most of us would like to live forever. At least that’s what I think when I see how old people are clinging to their lives. On the other hand, if all of us would live forever, while producing more offspring, earth would soon overflow. So the solution, if we get eternal life, would be to have no children anymore.
This, however, is in contradiction to Darwin’s evolution. We need to reproduce, to mix our gene pool, and adapt to the changes in environment. Evolution is brutal, too. It’s all about survival of the fittest, of trying to beat the competitor and make sure that my own genes reproduce. Mankind is no exception among the other species. The history of mankind is a history of wars, of killing one’s enemies. Today this has been ritualized; the Geneva Convention describes what’s allowed and what’s not. But this is still far from perfect, frequently broken, abused, or ignored.
The conclusion is, then, that we will be ready for eternal life when we will have reached perfection - no need for evolution anymore. In perfect state there is no need for competition, for beating or killing the competitor anymore. Unfortunately, we still have a long way to go. But if we can get rid of aggression, of getting our satisfaction from working together to create new things instead of competing against each other, we have come at least a little bit closer to perfection.