Evolution seems like a touchstone for a person's willingness to put reason first both because it contradicts the creation stories in most religions and because it requires us to accept that the universe just doesn't care about us - or about any other species actually.
In arguing for evolution - as we must do - there's a risk that we position evolution as the final frontier in the expansion of rational thought into territory formerly occupied by religion. Of course it isn't. Rationalism accepts no limits to the application of reason.
My thoughts were drawn to this by reading Nigel Willmot's article - The atheists' revolt - on the Guardian website (http://commentisfree.guardian
Martin Luther provoked a fierce backlash from the Catholic Church. Today's backlash is more likely to come from the Islamic world and may, in time, be every bit as fierce. We must stand by our principles. We must also find ways of talking to our opponents in ways that lead us, and them, away from violence.