The main cause of fear of death is lack of understanding. We should have a comprehensive understanding of life after death through contemplation.
Both mind and Spirit survive a man’s physical death. Death is just an exit, a point where our evolution enters into another phase. Logically, mathematically, and scientifically, energy (Spirit) is indestructible; form may change but substance never changes. This Spirit is birth-less and deathless. The physical body, various senses, and the mind are merely outer covers of the innermost Spirit.
According to the law of conservation of energy, it is impossible that energy (Spirit) can ever be destroyed. Hence, there must be rebirth. Just as we move from one house into another, so also the Spirit passes from one physical body to another. Commenting on rebirth, world-renowned Swami Sivananda of Rishikesh, India said: “If we deny pre-existence and rebirth and take into consideration that life begins with this birth only and ends completely with the death of the body and there is nothing more, then it will be no compensation for the virtuous man who has done noble actions and for the wicked man who has done crimes. The chain of cause and effect, antecedent and consequence, will be broken abruptly. There will be terrible injustice everywhere.” (quoted in Building a Noble World, p. 15)
We can surely overcome fear by actually realizing the essential indestructibility of our own inner Spirit. This realization will not only overcome fear but also confer bliss and peace. Although everyone has this immortal inner Spirit, very few people are able to get in tune with it. What comes in the way of experiencing the ever present inner Spirit? The answer is: the weaknesses of the mind such as anger, greed, hatred, malice, lust, jealousy, and pride. Once this “dust” in the form of various weaknesses is removed from the “mirror” of the inner Spirit, the mirror shines forth/the inner Spirit is experienced. One great way of removing the said “dust” is to cultivate sublime virtues by such practices as trying to relieve other people’s distress by selfless service, sincere prayer, satsang/company of a noble being, and meditation on the inner Spirit. Know that there is no fear in the inner Spirit. Once you experience your own inner Spirit, fear leaves you. So take refuge in your Spirit within.