I have often been told by believers that they cannot imagine a motive for any of these things [to strive for excellence, create beauty, foster love, diligently build (rebuild) the ideal of civilization] without the certainty of God and eternal life. Yet, for me, this very lack of certainty is why these things are of vital importance.
I found a dichotomy of equal difficulty being recapitulated as I wrote Flight of the Vajra. In that story there are two major factions of humanity: the Highend, who have embraced the transcendental possibilities of technological progress to varying degrees; and the Old Way, who feel the only real transcendence is something that comes from within, and cannot be proxied or prosthesized. You could become immortal by backing up and serially restoring your intelligence across multiple bodies, but why bother if you were doing that for the sake of living a life that was fundamentally empty and uncreative to begin with? (One insight I had is that those who can do something like that eventually choose more and more to do nothing but that, and soon everything except protecting one's own skin becomes secondary and eventually falls off the map altogether.)
One mission I set for myself when writing the book was to find a way to say that this is not a case of one side being wholly right and the other being wholly wrong. There are very good reasons to enrich our lives with technology, and other very good reasons to put it aside when we can. I wasn't interested in constructing a strawman argument in which technology is simply used as a whipping boy for all that is wrong with what happens, or where the Old Way were simply being contrarian fools. What mattered more was the quality of the arguments each side brought to their particular end of the debate — that you can argue badly for a good cause and vice versa. Each side has its dogmas and its profundities.
With the passage I quoted, it is not a question of the atheist approach being right and the theist approach being wrong, or vice versa. It is about each taking the best possible approach to the problem out of their particular point of view, for the sake of the life being lived. Crises of faith, or renewals of same, are generally not elective; once they happen, they have to be dealt with from the inside. We do not generally choose our prejudices, but we can choose how to embody, confront, or transcend them.
And in a civil society, the presence of one should not automatically crowd out the other, and it generally does not — both theism and atheism thrive side-by-side, each responding to the presence of the other. The believer is important because of his faith; the atheist important because of her skepticism; the panopoly provided by both of them together, indispensible. The sparks thrown off by their contrasts are as interesting as anything provided by either of them alone.