Freedom! An Academic Issue...
Le me add a footnote: faculty at universities do not have a primary duty to state funding institutions, other state instruments, or the students' parents - our primary duty is to our professional obligation to represent honestly and fairly the extent and boundaries of our academic knowledge, to advance that knowledge, to inform the students and to enable the students to critically examine the issue for themselves.
There is absolutely no obligation whatsoever to let the students be comfortable in their prejudices or to respect their parents or state representatives views, except in so far as the existence of those views is of some sociological interest or happens to coincide with our professional position on the relevant issues.
It is arguably a matter of personal courtesy to not be overtly confrontational or harsh in evaluating competing viewpoints, you can tell someone that their personal belief in astrology is wrong and misguided without telling them that they are total fucking morons.
As for matters of faith - well if you have faith, then you should be strong enough to embrace the test of faith that contradictory facts present. If the Red Queen can do it, so can you.