Via Andrew Sullivan, short essays from various scientists, philosophers, theologians, etc. on the question. I like Stephen Pinker's answer the best:

Yes, if by "science" we mean the entire enterprise of secular reason and knowledge (including history and philosophy), not just people with test tubes and white lab coats.

Traditionally, a belief in God was attractive because it promised to explain the deepest puzzles about origins. Where did the world come from? What is the basis of life? How can the mind arise from the body? Why should anyone be moral?

Yet over the millennia, there has been an inexorable trend: the deeper we probe these questions, and the more we learn about the world in which we live, the less reason there is to believe in God.

Start with the origin of the world. Today no honest and informed person can maintain that the universe came into being a few thousand years ago and assumed its current form in six days (to say nothing of absurdities like day and night existing before the sun was created). Nor is there a more abstract role for God to play as the ultimate first cause. This trick simply replaces the puzzle of "Where did the universe come from?" with the equivalent puzzle "Where did God come from?"

What about the fantastic diversity of life and its ubiquitous signs of design? At one time it was understandable to appeal to a divine designer to explain it all. No longer. Charles Darwin and Alfred Russel Wallace showed how the complexity of life could arise from the physical process of natural selection among replicators, and then Watson and Crick showed how replication itself could be understood in physical terms. Notwithstanding creationist propaganda, the evidence for evolution is overwhelming, including our DNA, the fossil record, the distribution of life on earth, and our own anatomy and physiology (such as the goose bumps that try to fluff up long-vanished fur).

For many people the human soul feels like a divine spark within us. But neuroscience has shown that our intelligence and emotions consist of intricate patterns of activity in the trillions of connections in our brain. True, scholars disagree on how to explain the existence of inner experience—some say it's a pseudo-problem, others believe it's just an open scientific problem, while still others think that it shows a limitation of human cognition (like our inability to visualize four-dimensional space-time). But even here, relabeling the problem with the word "soul" adds nothing to our understanding.

People used to think that biology could not explain why we have a conscience. But the human moral sense can be studied like any other mental faculty, such as thirst, color vision, or fear of heights. Evolutionary psychology and cognitive neuroscience are showing how our moral intuitions work, why they evolved, and how they are implemented within the brain.

This leaves morality itself—the benchmarks that allow us to criticize and improve our moral intuitions. It is true that science in the narrow sense cannot show what is right or wrong. But neither can appeals to God. It's not just that the traditional Judeo-Christian God endorsed genocide, slavery, rape, and the death penalty for trivial insults. It's that morality cannot be grounded in divine decree, not even in principle. Why did God deem some acts moral and others immoral? If he had no reason but divine whim, why should we take his commandments seriously? If he did have reasons, then why not appeal to those reasons directly?

Those reasons are not to be found in empirical science, but they are to be found in the nature of rationality as it is exercised by any intelligent social species. The essence of morality is the interchangeability of perspectives: the fact that as soon as I appeal to you to treat me in a certain way (to help me when I am in need, or not to hurt me for no reason), I have to be willing to apply the same standards to how I treat you, if I want you to take me seriously. That is the only policy that is logically consistent and leaves both of us better off. And God plays no role in it.

For all these reasons, it's no coincidence that Western democracies have experienced three sweeping trends during the past few centuries: barbaric practices (such as slavery, sadistic criminal punishment, and the mistreatment of children) have decreased significantly; scientific and scholarly understanding has increased exponentially; and belief in God has waned. Science, in the broadest sense, is making belief in God obsolete, and we are the better for it.