One of the great assets that religion has is its promise of everlasting life after death. Whether it is an eternity in hell or heaven, reincarnation, our lives (for the price of belief and submission to a system of subsequent beliefs) can be continued after death.
Notice, however, that everlasting life is granted only after you are dead.
Religion does not give you everlasting life, immortality, when you are still living.
If religion really had the power to grant you immortality, then it would do so, magically, in this existence and not some other. If god really has the power to grant you everlasting life, then he could do so in this life and in not some other -- it wouldn't be beyond his power.
If religion really could deliver everlasting life while you are still alive there would be no sense of loss, no fear over dying, and no graveyards.
Religion only promises to deliver immortality after you are dead where no amount of scientific measurement can be done. No amount of metric gathering can be done. No amount of verification can be done to assure one that life does indeed continue after death. And no evidence can be collected to prove there really is everlasting life after death.
Religion only promises immortality after you are dead because it exploits our fears of extinguishment and gaps in our knowledge. It is a promise built on ignorance and fear.
The promise of everlasting life is an empty promise.