Yeah, I think it's pretty easy to demonstrate: the Christian accepts that there was a time when it was immoral to work on the Sabbath, and that it was moral to kill a person who worked on the Sabbath. The Christian accepts that today it is NOT immoral to work on the Sabbath, and that it IS immoral to kill someone who happens to perform any work on the Sabbath. Therefore, there are some actions that cannot, in and of themselves, be moral or immoral. Context (in this case, god's command) determines whether an action is moral or not.
"Well, evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts don't go away when scientists debate rival theories to explain them. Einstein's theory of gravitation replaced Newton's in this century, but apples didn't suspend themselves in midair, pending the outcome. And humans evolved from ape- like ancestors whether they did so by Darwin's proposed mechanism or by some other yet to be discovered."
-Stephen Jay Gould
-Stephen Jay Gould
