I'll make it simple... the theory of evolution, just as all science, is based on fact. If my child attended a science class in which the teacher taught anything else besides fact based science, then I would probably pull my child from that class. I'm not opposed to other ideas being taught about religion or philosophy, but that doesn't belong in a science class.
Let me put it this way, the whole point of science is to discover the why's and how's of this world based on tangible facts. If you were to bring up some spiritual based aspect in a scientific forum, you are pretty much dismissing the facts and asking your students to consider ideas based on beliefs which can never be proven.
