Why spiritists don't fear death
From the book: Heaven and Hell – Allan Kardec

The spiritism doctrine completely changes the way we look at the future. The future life is no longer a hypothesis, but a reality. The state of souls after death is no longer a system, but the result of observation. The veil has been lifted: the spiritual world appears to us in the fullness of its practical reality. It was not men who discovered it by the effort of an ingenious conception, but the inhabitants of that world themselves, who come to describe their situation to us. Thus we see them in all degrees of the spiritual scale, in all phases of happiness or misfortune; and we witness all the vicissitudes of the life beyond the grave.
This is why spiritists face death with calm and serenity in their last moments on earth. They are comforted not only by hope, but by certainty. They know that the future life is but a continuation of the present life, albeit under better conditions, and they await it with the same confidence with which they await the rising of the sun after a stormy night. The reasons for this confidence come from the facts which they have witnessed, and from the agreement of these facts with logic, with the justice and goodness of God, as well as with the innermost aspirations of man. To the spiritists, the soul is not an abstraction: it has an ethereal body, which makes it a definite being, capable of being conceived and embraced by thought, which is already much to fix ideas about its individuality, its aptitudes and its perceptions.
The memory of those who are dear to us rests on something real. We no longer represent them as fleeting flames that say nothing to our thoughts, but in a concrete form that shows them to us as living beings. Moreover, instead of being lost in the depths of space, they are all around us, for the corporeal world and the spiritual world are in perpetual relationship and mutual assistance. Since there is no longer any doubt about the future, the fear of death loses its raison d'être. The spiritism faces death in cold blood. He sees it as a liberation, for it is the gateway to life, and not to nothingness.