It will not do to advance the ecumenicist argument that in spite of their differences, all religions are God-given because they are all rooted in a longing for the transcendent. That is exactly the point. The desire for transcendence--something to make us forget the finiteness of our lives--is a human trait. It may even be our defining trait as a species. The so-called "God gene" is nothing more than the very human longing for immortality.

Mark Twain, in an 1870 letter to his fiancee, wrote, "How insignificant we are, with our pigmy little world!...Does one apple in a vast orchard think as much of itself as we do?...Do the pismires argue upon vexed questions of pismire theology--& do they climb a molehill and look abroad over the grand universe of an acre of ground & say, `Great is God, who created all things for us.'"?

In his new book God Is Not Great, Christopher Hitchens makes the obvious point (obvious to anyone who no longer believes in the tooth fairy) that religion began as an attempt to explain the inexplicable in a distant era when humans knew virtually nothing about science. Zeus's thunderbolts accounted for lightning. Spring arrived with Persephone's return from the underworld. With these divine explanations came elaborate, often bloody rituals to placate the gods and ensure the safety of humans. If we sacrifice a virgin, the harvest will be bountiful.

But that does not explain why so many human beings persist in needing religion now that we know what causes lightning and are able to produce enough food to stuff ourselves into obesity and heart attacks. Indeed, many people need religion so badly that they simply reject any evidence-based science that challenges their faith.

The only real explanation for the persistence of religion, as Twain observed, is our inflated opinion of ourselves--coupled with unwillingness, as individuals and as a species, to contemplate our own extinction. This explanation is often overlooked by hard-core atheists as well as the religious, for the simple reason that atheists are no more comfortable confronting death than anyone else is.

Death is often assumed to be a more disagreeable prospect for an atheist than for a religious believer, because we have no expectation of reunions with our loved ones in heaven. I have never been entirely convinced, however, that religious believers are as certain about eternal life as they pretend to be. Consider the willingness of so many very old people to endure horrific chemotherapy for advanced cancer--with no possibility of a better outcome than a few more painful weeks or months of life.

If people truly believed in an afterlife, they would be happy to have lived into their 80s and ready to join their departed loved ones. But--go figure!--very few believers seem eager to cross over to that "beautiful shore" where everyone is supposedly waiting to meet and greet the new arrivals. Apparently most sane men and women, whatever their hopes and however accustomed they are to hearing the clergy preach about the glories of the afterlife, prefer even the most miserable certainty of the here and now to the blissful but uncertain prospect of the "sweet by and by" alluded to in the famous 19th-century hymn.

Whether we are talking about reincarnation or "rapturing" in heaven with those deemed worthy at the Last Judgment, all religions make the implicit or explicit promise that death is not the end. We invented gods in the dawn of the human species not only to explain natural phenomena we did not understand but to fulfill the delusion (and the wish) that there is some way, courtesy of one god or another, for our ashes to be made flesh once again.

Of all the things I find puzzling about faith, the most puzzling of all is the conviction of so many believers that this life has no meaning unless it is to be followed by another life. To me, the absolute certainty and finality of death are what infuse life with meaning.

We have only a finite amount of time to love, to work, to create, to enjoy the beauties of nature, and to revel in the greatest achievements of our fellow human beings. What we leave behind--whether we leave children; art; works that add to the sum of human knowledge; or the memories of those who loved us--is the meaning of our existence, and it is meaning enough.

All of the visions of paradise promised by various religions pale by comparison with the tender touch of one human hand on another.

As William Wordsworth wrote in his great ode, "Intimations of Immortality from Recollections of Early Childhood:"

The clouds that gather round the setting sun
Do take a sober coloring from an eye
That hath kept watch o'er man's mortality;
Another race has been, and other palms are won,
Thanks to the human heart by which we live,
Thanks to its tenderness, its joys and fears,
To me the meanest flower that blows can give
Thoughts that do often lie too deep for tears.