We cannot live by reason alone. This is why no quantity of reason, applied as antiseptic, can compete with the balm of faith, once the terrors of this world begin to intrude upon our lives. . . . This has led many of us to conclude, wrongly, that human beings have needs that only faith in certain fantastical ideas can fulfill. It is nowhere written, however, that human being must be irrational, or live in a perpetual state of siege to enjoy an abiding sense of the sacred. On the contrary, I hope to show that spirituality can be--indeed must be--deeply rational, even as it elucidates the limits of reason.
End of Faith, Sam Harris.