As a large number of issues in contemporary biology are controversial, science teachers in so-called 'faith' schools need to know what their employers regard as 'doctrinal correctness'. Any effective response to the rise of fundamentalism and atheism needs to answer challenges, take scientific knowledge into consideration and re-think traditional beliefs, expressing them in new and more accurate ways. Nevertheless, in an attempt to achieve such ends, these schools should not be permitted to resort to teaching a biased version of mainstream science, especially biology, omitting or distorting facts and theories not in accord with their principles or religious beliefs. Here, Darwin's reasons for becoming an agnostic are outlined.