Why do I disagree with the demands of religious fundamentalists regarding the teaching of evolution? I believe that what they are objecting to are the methods of science, and this problem has appeared more quickly with biology than with other natural sciences. If physics and other natural sciences are looked at very closely, they too would probably lead to the same political problems as are faced by biologists. For example, modern physics is based on randomness being a built-in part of the universe. This randomness is something that many religions deny strongly. Will we need to preface the teaching of quantum mechanics with a statement that this is an "unproven theory"?
Fundamentally, the people who object to the teaching of evolution are objecting to the methods of science, or more charitably, they do not understand the nature of science as a way to understand the world we live in. Religious critics attempt to dismiss Darwinian evolution as "only a theory". What critics do not seem to realize is that their criticism applies to all of science. It is all "only a theory", including Newton's laws of motion, the periodic chart of the chemical elements, the atomic model of matter, and all the rest of science. That is the nature of science. We look for consistent theories that are testable by looking at the natural world. We do not allow for supernatural explanations, and that appears to be our major fault as regards our critics. We do not assume the Bible is true and then attempt to look for explanations consistent with the biblical accounts.
Science is a way of seeking "truth", just as is religion. Usually religion and science are concerned with different areas of life, but sometimes there is an intersection. What are the methods of science and what are the methods of religion? Science allows consideration of tools and data from only the natural world, not the supernatural world. It builds "models" to describe what we observe. Such models are called "theories". For example, Newton's "Law of Gravitation" is a mathematical model for forces of attraction between physical bodies in space. From it we can predict the future positions of such physical bodies. For the most part, Newton's law correctly predicts such future positions, but not always. When Newton's law was discovered to not always predict correctly, as with the orbit of Mercury about the Sun, modifications were made to the theory. Scientists do not say that Newton's law of gravitation is "true", but rather that it (usually) predicts correctly what we observe in the universe. Those who are looking for absolute truth from science are doomed to disappointment. That is not in the nature of science.
The following is taken from Carl Sagan's book The Demon-Haunted World:
Science As A Candle In The Dark.
"Humans may crave absolute certainty; they may aspire to it; they may pretend, as partisans of certain religions do, to have attained it. But the history of science - by far the most successful claim to knowledge accessible to humans - teaches that the most we can hope for is successive improvement in our understanding, learning from our mistakes, an asymptotic approach to the Universe, but with the proviso that absolute certainty will always elude us."
Returning to evolution, it is a theory that continues to develop. There is feedback from our observations of the world. Biologists do not claim to understand everything about the development of life on this planet. They are still trying to fine tune their model. But the evolutionary model has done a better job of predicting what we see than does any other model that has been used. Every model must be one that makes predictions that can be tested against physical reality. If a model cannot do this, then it is not a scientific model or theory, and consequently it does not belong in the science classroom.
The supernatural world is fundamental to religion as a means of understanding the universe and the role of human beings in it. But it is not science and it is destructive of science to allow anything other than natural world data, tools, and explanations into science. If someone objects to this on account of their religion, then I would prefer that they simply pull their children out of science classes rather than destroying science itself. Just because some aspect of science disagrees with your personal religion is no reason that scientists should have to change the science. To speak of "faith-based science" is an oxymoron. The proposed new laws and guidelines in places such as Kansas amount to saying that religion trumps science in the science classroom.
Should students be exposed to these differences between religion and science? Yes! But science class is not the place! I believe there should be "great issues" forums or classes in which these differences and other fundamental problems of life and death could be discussed with the various sides all being heard. This is called a philosophy class. I suspect that religious fundamentalists would also object to such a forum or class, as they already have the truth and would rather not have their children exposed to other possible perspectives.
Do scientists implicitly deny the existence of God? My personal (and admittedly biased) sampling is that most scientists are skeptics as regards the standard organized religions. But they are also in awe at the universe in which we live. I think the perspective of the physicist and philosopher Paul Davies in The Mind of God would come closer to the belief system of many scientists. Most of us find the standard theology of the major religions to be too simple to explain the universe in which we live. As another source of my own personal skepticism, see Karen Armstrong's A History of God. It and other books have led me to a very skeptical perspective on the "truth" of Judaism, Christianity, and Islam.
Regarding "Intelligent Design", it is a possible explanation. But there is no way of testing it, because it says that life as we know could not have arisen without divine intervention. "Intelligent Design" is a philosophical statement about the universe. It cannot be a scientific theory until it is able to make predictions which can be compared against physical reality. In addition, computer modeling that has been done to-date shows that very complicated and sophisticated structures can arise out of simple rules given a reasonable but large amount of time. See the work of John Conway (cf. "The Game of Life"), Stephen Wolfram, and others.
Scientists do not claim to know the entire truth about the universe. Rather, science is a self-correcting process for obtaining an increasingly accurate picture of the natural world. We do not have the complete truth, but have a process for improving what we know. We also do not claim to understand why the universe came into being.
Is there a God? I do not know! But if there is some kind of force of this kind, exterior to us, I certainly would not try to explain it in anthropomorphic terms in the way done in most established religions. I find the explanations of the world given by so-called "primitive cultures" as convincing about the meaning of the universe as I do the explanations of most current established religions. I also find it arrogant of the world's religions to assert they know the mind of God. I do not believe them! In general, I remain a skeptic as concerns the major religions of the world.