The popular media and many in academia often overstate the role that religion, and its supposedly unique qualities, has played in recent acts of terror. In this article, I argue that the notion of religious violence is unhelpful and that there is a more useful concept that we can utilize to draw out the values and ideas that play a role in the move to violence in both religious and secular groups. From a series of case studies on religious and non-religious groups, I have drawn out an alternative framework for investigating and learning from the role that beliefs play in motivations and justifications for terrorism. This framework uses the concept of non-negotiable (or “sacred”) beliefs. It is as applicable to secular as it is to religious groups, and can show us much more about how such beliefs can contribute to violence.