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. If I were to teach again in a school with a strong Christian bias, could I give an intellectually honest account of evolution and other biological processes that did not infringe any Church doctrines or biblical statements? Frankly, even with the best will in the world, and after searching high and low for theories that fit, it would be difficult to do so without steering clear of some important issues and stifling open-ended discussions.