Why don’t people live to 960 years of age any more, like they did back in the days of Methuselah and Noah?
Because of the wickedness of humanity on the earth during the time of Noah right before the flood, God reduced the age of humans to no more than 120 years (Genesis 6:3). This did not take effect immediately.
Gradually over time you see the numbers of human years being reduced throughout the genealogies and generations. The depravity of humanity has also produced sicknesses that lead to death faster. All of this is part of the sin condition in humanity.
God never rescinded his judgment of no more than 120 years. Even today people living to 100 years of age are the exception, not the rule. Because of the grasp sin has on us, this rule of 120 years maximum will stay in place.
Things aren’t getting better as far as our holiness level or our morality. God has no reason to give us the privilege to live longer. It doesn’t seem that living longer makes us any better. Even with the advances humans make in science and medicine, we still don’t see anything past 120.
The best hope for anyone is to share the gospel and to know Christ in this life. Because even after you pass away, God has promised resurrection of the body and soul. Christians live with Jesus forever in heaven even after physical death.
The second death, spiritual death, separation from God, can be avoided through receiving the gospel and serving Christ now. The time is short, so let us tell everyone about the cure for short life.