"O child of noble family, now what is called death has arrived.  You are not alone in leaving this world. , it happens to everyone, so do not feel desire and yearning for this life.  Even if you feel desire and yearning you cannot stay..." ~ from "The Tibetan Book of the Dead"

    A major difference between spiritually developed people and materialistic ones is that spiritual people do not fear death of the physical body while materialistic people do.  
    People who don't believe in an afterlife, and even some who do but are uncertain, understandably fear death.  Unfortunately, that fear of death often makes them an instrument of death to others and, indirectly, to themselves.  People who fear death will fight to get food,water, land, whatever they think they need to keep their physical body alive.  They will go to war to protect their lives and the lives of "their people" even though many of them understand that, by doing so, they are putting themselves at greater risk.  And the very wealthy, who are usually part of this group,  they will pay huge amounts of money to add just a little time to their physical lives by doing things like getting a heart transplant when eighty years old and, by doing so, deny a younger person the transplant that could add twenty or thirty years to their life.
    Spiritual people are different.  They don't fear death of the physical body because they know they have a spirit and soul and they know the spiritual worlds exist.  Jesus showed no fear of death and forgave those who put him to death.  Buddha thanked those who poisoned him before he died.  Martin Luther King Jr.  seemed to know his death was coming but made no attempt to hide from it.
    It must be noted though that not fearing death is not the same as believing that dying for your faith, as many early Christians did and many modern Muslim terrorists do, does NOT put you on an express train to heaven.  The martyrdom of some saints may have got them moving toward heaven, but only because it was the last act in a life of spiritual devotion.  Martyrdom by itself does not accomplish that.