I always find it fascinating, yet predictable, that some folks are never satisfied with the work scientists are doing, despite the fact those same folks barely, if at all, understand what science is all about.
if your cells worked right and kept dividing forever you could be biologically immortal. you would probably get killed by something other than ageing eventually though, if you didn't take further preventative measures. I think NMN in combination with TA-65 might make humans immortal. because NMN makes sure that cells work the way they have to in order to keep an organism alive, and TA-65 makes sure they can divide forever and hence continue to do so forever. there have been some rather interesting studies with NMN on mice, it actually made them look younger. they still died though, I suspect because their cells stopped being able to divide. NMN has been talked down lots because people are afraid it will contribute to overpopulation.
Genetic Engineering may lead to Immortality as all aging is the decay of the ability to make proteins by the cell, if the genes are repaired that make all proteins and are never damaged then technically you could stay in the same health and genetic status as a 18 year old forever. Possible Method = http://www.scienceforums.com/topic/36231-methods-of-biological-immortality-2019
Theoretically we could become immortal. There is already an immortal Jellyfish Please Register or Log in to view the hidden image! Wikipedia Then there is the compound single celled slime mold which have survived billions of years, constantly renewing itself. Please Register or Log in to view the hidden image! https://rhizome.org/editorial/2016/aug/16/slime-intelligence/
they understand it doesn't get them the desired results most of the time. although there are exceptions.
Some things just aren't possible to achieve and I believe immortality is one of them. There is always something that can kill you, therefore immortality isn't achievable. We also can't travel to another galaxy or distant star system and we also can't travel back through time or even bring a relative back from the dead. I also don't believe in God btw because I think he just doesn't exist.