Well, you've hit the nail on the head as to the very "inspiration" for the invention of religion, fear about our ceasing to be.
When we are healthy, mentally as well as physically, it is natural to want to continue being, existing, living, "forever and ever," as the prayers put it. When we become desperately unwell, that powerful desire weakens.
It's not surprising that religion, its gods, its heavens, its hells, its eternal life, evolved from ancient times when illiterate people who were still healthy were scared about losing their own lives when they observed others devolve into illness and death, into non-being.
In their imaginings they created the notions of religion, and the idea of living happily forever was part of that. It was comfortable, but it was false comfort. There was no reason to it.
Still, it lingers. It's like a virus. It's contagious. In spite of all scientific discoveries, in spite of any lack of supportive evidence, only "faith and hope," people continue to subscribe to the ancient feel-good notions precisely because they make them feel good--until they become so sick that they tire of the struggle of living. There are innumerable examples of that.
It's natural to want to keep living as long as life is good, or ok, or if we can hide in booze or drugs, or other deceits like religion. As Frank Sinatra once said, "Whatever gets you through the night, a song (his preference, of course), a prayer, or a bottle of Jack Daniels." There are other saner, more realistic, healthier choices.
Why should we fear nothing? And our observation of all the life on this planet proves that the end of life means nothing to that life. The inventions of religion are selfish conceits falsely placing us above all other living things.
A good Christian bishop, John Shelby Spong, puts it best: "Live fully! Love wastefully! And become all that you can be!" I will add, "While you live."
 See the comment by "gilhow" on 2010-01-07 at 5:00.