I know that He exists.
Somewhere -- in Silence --
He has hid his rare life
From our gross eyes.
'Tis an instant's play.
'Tis a fond Ambush --
Just to make Bliss
Earn her own surprise!
But -- should the play
Prove piercing earnest --
Should the glee -- glaze --
In Death's -- stiff -- stare --
Would not the fun
Look too expensive!
Would not the jest --
Have crawled too far!
I find Dickinson to be the most striking of poets because she inhabits the knife edge of agnosticism (about matters both metaphysical and theological), compared to which atheism is a cozy nook of fundamentalist certainty. From a purely external point of view, with respect to, say, church attendance or time spent in prayer, the agnostic and the atheist may appear indistinguishable, but subjectively there is all the difference in the world. Like any poet ought to, Dickinson sees this mystery, among other wonders, through fresh eyes, but with words that detonate upon reading, compounding gunpowder with the austerity of haiku. She may not have gazed upon God, but she sure did see the gaping God-shaped hole in the universe.
Jerry Coyne has written, in The New Republic, another devastating critique of both intelligent design and the often touted compatibility of religion and science. His lengthy but rewarding essay begins by reminding us that Charles Darwin and Abraham Lincoln were born on the very same day, February 12, 1809. The universe held its breath--can there have been any more world-historically significant day in the two centuries since? I will not attempt to summarize his trenchant analysis; a few comments will suffice.
Coyne notes that the fact that some scientists harbor conventional religious beliefs says more about the psychological inconsistency and talent for rationalization of human beings than it does about any real philosophical family resemblance. As he puts it:
True, there are religious scientists and Darwinian churchgoers. But this does not mean that faith and science are compatible, except in the trivial sense that both attitudes can be simultaneously embraced by a single human mind. (It is like saying that marriage and adultery are compatible because some married people are adulterers.)
Science does not directly disprove religion, but it has gradually removed the rational need for religion to attempt to explain any number of things about how the universe works. To be sure, there are things that science cannot explain, at least not yet, such as the origins of life or of the universe. But religion does not explain these either; it does offer purported descriptions of these origins, but this is not rational explanation, which depends on testability and experiment. To say that God created the universe is not to explain how the universe is created; it is, rather, to say, "Stop asking, in rational terms, how the universe was created."
Anyone who cares about psychology ought to take religion seriously, given that the great majority of human beings who have ever lived have been religious. The fact that a minority of people are unpersuaded no more undermines the centrality of religiosity to human nature than the occasional occurrence of voluntary celibacy negates the significance of sexuality. Religion arguably meets powerful needs for spiritual integrity of the self and the world, as well as underpinning morality and communal life. This is not to say that these needs cannot, some day, be met in different sorts of ways than they traditionally have been, but we ought not to overlook the needs themselves.
The problem, as Coyne writes, is that most religions go beyond moral, communal, and spiritual experiences to make specific empirical claims about the universe (involving, of course, creation, virgin births, heaven and hell, etc.). It is these claims that are specifically incompatible with science because they are immune to possible disproof by experiment (these claims have also led to much of the historical factionalism and violence that gives religion a bad name). The question is whether religion in the future can relinquish these empirical claims without losing its benignant influence for many people.
It's awfully hard to prove that something doesn't exist. Even so, I am virtually certain that, say, centaurs do not exist anywhere in the universe. I am so certain because the likelihood of intelligent life elsewhere (already a huge long shot of course) taking the form of such earth-generated mythological creatures is very close to nil, even if it cannot logically be shown to be zero.
I am very much less certain about God than about centaurs, largely because throughout history the notion of a supreme being has been so amorphous, and has taken so many diverse forms, that it is hard to know what we are talking about. In fact, it may be more accurate to liken the possibility of God not to any specified phenomenon such as a centaur, but to the potentiality of other intelligent life of whatever (in)conceivable form anywhere in the universe.
I personally have not encountered incontrovertible evidence, whether in my own subjective experience or available objective data, for the existence either of God or of extra-terrestrial intelligence. I cannot disprove their existence, and I have no interest in doing so, but I also don't go about my affairs under any specific assumption that they do exist. I try to do what's right, but I do it because it seems right, regardless of alleged supernatural justification. The fascinating and sometimes bewildering part is that while only a very small and eccentric fraction of my fellow human beings believe in UFO's, a rather large proportion of my earthly cohorts believe in God, so it behooves me to try to ascertain why that is and how we can all get along on this, the only world we really know.