If you study engineering and in particular mechanical engineering, one of the first theories you learn about is design life. Design life is the length of time that something will last with normal maintenance. There is no concept of perpetual machine life in engineering, although there are perpetual rumors and urban legends of perpetual motion machines or energy sources. THEY DO NOT EXIST. Such a device would violate proven physical and mechanical laws.
Everything in our world has and follows this concept of design life. Our universe was once thought to be a product of "The Big Bang". In this scenario, the world exploded from a single point and continued to expand until the stars and solar systems ran out of steam and begin collapsing back in and this process would continue on for eternity. It was much like shooting a bullet straight up in the air and finally when the gravitational pull overwhelmed the momentum of the bullet, it would fall back to earth. So too our universe would fall back in on itself and eventually explode again and make the same cycle again.
Today, we know that the expansion of the universe is not slowing down but rather speeding up. Now there is a theory that at some point as the universe expands it will continue to cool and at some point when all atomic motion ceases, yep - it dies. We do not know, there ae new concepts we recently learned of called dark energy and dark matter that actually make up about 95% of the stuff in the universe, we just cannot see, smell or feel it but mathematically it has to exist.
Man too obviously follows this same law however our design life varies. Even if we could stumble on the eternal life gene, we still would have to beat the odds of being run over, shot, car crashes, murder etc, you get the picture. Bottom line we cannot escape death either.
There is a very perplexing thing we must consider, the world as we know it(scientifically), is nothing but motion. When we die, even the very atoms of our bodies decay into other types of atoms and molecules. The evidence is overwhelming that we exist after physical death.
It has been said there are no atheists in foxholes. When the bombing begins so do the prayers.
Every civilization has a sense of a hereafter, most have a god or gods that they worship or have a sense that man is the god himself.
Death bed confessions are upheld in most courts. Why do you think that is?
Men and women of all cultures call out to God in their last moments of life, regardless of their religious experiences.