In Theory

When someone says to me: "It's just a theory," what I hear is: "I believe in science, and I don't want it to be amoral."

For my part, I was not raised within a religious tradition that required the Bible to be an inerrant historical document - it was a religious text, and that was that. So I could rely on science texts to tell me what is, and turn to scriptures to inform me as to what ought to be. And as it turns out, the broad majority of people tend to believe in the accuracy of the scientific method to explain the world to us - it's important to keep in mind that for many people their disagreements with the scientific community are not about the efficacy of science itself - it's with the honesty of the scientific establishment, which is often viewed as pushing Leftist and/or atheistic agendas.

For almost all of the few creationists I know, the understanding is that the Bible exists  to tell them both what was (and to a certain degree, what is) and what ought to be - and that these two things are inseparable. So if the Bible is not an accurate account of what was, then it is not a reliable guide of what ought to be. So threatening one is often viewed as an attack on the other. While for many of us there is no workable path from "Mankind evolved, over tens of thousands or millions of years from an apelike ancestor on the plains of what is now Africa," to, "There is nothing fundamentally wrong with rape, murder and/or genocide;" for people who understand that the literal historicity of the Genesis account is what makes the Ten Commandments any more compelling than any other rule someone might come up with, anything that undermines Biblical inerrancy is a dire threat.

And it's important to understand that many religious people do not have a problem with the idea science - but they are motivated to doubt the accuracy of scientific findings that fly in the face of the worldview that they hold. By the same token, a lot of effort goes into attempting to square their understandings with modern scientific practices, and any discoveries that appear to support their beliefs are widely touted.

In my estimation, if the religious were as scientifically ignorant as they are portrayed, they wouldn't bother attacking the bona-fides of the ideas that the disagree with - they'd simply discount the usefulness of the whole enterprise. The goal of the secular shouldn't be to use science as a weapon against the beliefs of others. It simply prolongs a fight that no-one can win.