While Islamist forms of terrorism have received a great deal of attention from scholars, insider accounts by indigenous scholars are still under-represented. This Special Issue of the Asian Journal of Social Psychology brings together three articles on religious terrorism and sacred violence in Indonesia, the world's most populous Islamic state. They bring together qualitative methods, including interviews with terrorist members of KOMPAK and Jemaah Islamiyah (including the Bali Bombers), with quantitative methods using structural equation modelling to explain a national representative sample's attitudes towards sacred violence. The articles converge towards an indigenous theory of Islamist terrorism for Indonesia involving three steps: (i) existential threat (triggered by violence inflicted on Muslims, nationally or internationally, and perceptions of the impurity of the secular Indonesian government), (ii) self-categorization of the world into infidels and believers (thus arguing that the current situation is a state of war where violence against non-combatants is justified), and (iii) jihadi ideology as the trigger for turning existential threat into religious violence. It is the interpretation of scripture offered by trusted leaders, often reinforced by oaths of obedience, rather than scripture itself that fuels the indigenous psychology of violent (lesser) jihad presented here.