The last place I expected to hear that question was in the clean room of a semiconductor manufacturer, spoken by a technician whose livelihood depended on scientists being a lot smarter than he was. I soon found out that he really meant biologists were stupid for accepting evolution instead of creationism as the best explanation for the complexity of life, especially when it came to humans. That was my first exposure to the possibility that functioning members of modern society could reject, on the basis of faith, hundreds of years of painstaking observation, testing, and thought. As a trained physicist, I easily determined that for their explanation to work, various laws of physics also had to be wrong. Essentially, God was testing people's faith and their intelligence by whether they would find the ways the Universe worked that were consistent with the literal translation of his words as related in the Bible. That scientists had reached the different conclusions after hundreds of years of painstaking research, thought, and testing just proved that they lacked both faith and intelligence.
There is a parallel and oddly similar argument, which I've recently encountered as part of a belief system shared by some people in the sustainability movement. Basically, it says that the complexity of the Universe is so great that it transcends explanation in the terms used by science. Instead, we, like other creatures, already have everything we need to appreciate and be a meaningful part of the Universe, or at least that part of it that supports life. There are a small number of basic patterns in Nature, that we are already intuitively aware of, that allow us, if we want, to use minimal, non-destructive technologies to be an integral, healthy part of our planet's ecosystems. We don't need anything else, and it's pointless – and harmful to the Earth – for us to seek it. The bottom line: scientists are stupid and dangerous.
Science is fundamentally a means of describing and explaining experience in abstract form, an extension of how we humans use language to communicate information about our experiences. The invention of mathematics, writing, and computational tools has enabled science to become both explanatory and predictive, to an extent far beyond what any one mind or group of minds can comprehend. I believe it is this transcendence beyond personal, visceral experience that is at the heart of both the arguments I cited, despite the fact that science and technologies using it have resulted in a progressively more benign environment for at least some of us.
Two basic needs are not being met by the increased power over our personal environments that science, technology, and the leveraging of group effort through economies have enabled. One of those needs is for meaning in life; the other is for the ability of people to meet their basic needs through direct influence. It is no more meaningful to be a consumer and a producer in an economy than it is to be a manifestation of mathematical probabilities in a multiverse of matter and energy. Most of the time we must rely on governments and corporations to provide our safety and sustenance, often from places and using technologies we can never hope to understand or manage.
A deity such as a personal god provides an easy way to, at least in concept, meet both needs: You are special to the creator to the Universe, and because of that, you can convince him to take care of you. Alternatively, you might see yourself as an integral part of that Universe, without whom it wouldn't be the Universe; you have what it takes to survive in Nature because Nature is you – all that's needed is to create a local, more ecologically healthy environment where you can use it. Ironically, pure science does not pretend to be able to define such a subjective thing as life's meaning, nor does it rule out a more personal relationship with one's environment or any other.
When empowered with adequate technology (such as supercomputers), science can do a pretty good job of simulating large systems; and with proper translation into experiential terms, it can give us insights into the impacts of our actions that our minds and bodies are simply not capable of doing anywhere near as accurately. To be responsible, and have any hope of being true to the values that we define for ourselves, we need to match the power of our actions with our knowledge of their consequences, and science currently provides the most reliable way to do that. If we are uncomfortable with this dependence, we must find a way to scale back our influence on the world to a point we no longer need to depend on it. If we want to rely on a deity of dubious existence, we must be willing to reduce our impact on others so we won't hurt them if or when our faith is found to be misplaced (if the deity's existence wasn't dubious, we wouldn't have to depend on faith).
Ironically, science is showing that we must collectively limit our influence over other species or risk driving most of them, and us, extinct. A world closer to the one we evolved in will be a healthier world, but at the expense of much of the power we've spent centuries accruing. As the tools needed to maintain and monitor our artificial environments falter, become unusable, and are replaced with more natural ones, I expect that science will continue to occupy an important niche in human understanding, but in a form much more usable by the majority of people. Perhaps at that point we will all be scientists (most of us something closer to what we now call naturalists), and the question that opened this discussion will never be asked again.