This paper examines how religious education is delivered in the multi-religious Indonesian education system, which aims to promote piety and religiosity and strengthen the inclusive national identity. Employing multiple-case-study research, it examines how six state and private schools in Jakarta (Muslim-majority) and Bali (Hindu-majority) with different mixes of student ethnicity and religiosity accommodate and negotiate the vision of religious diversity. The findings show that contextualisation of religious education was present across schools between provinces and within the same provinces, even with similar student demography. This contextualisation which involves negotiation processes between schools, both as an institution and actors (such as teachers, students, and head teachers) and local cultures can be seen as an effort to accommodate religious diversity to achieve the vision of Indonesian Unity-in-Diversity. Schools' responses to religious education, such as through the provision of religious education and morning service arrangements, greetings and worship facilities, uniform policy, and the school ethos and policies, do not always accommodate all students' religious needs, specifically the minority and supra-minority religious groups. This case study of Indonesia with the contextualised school responses provides insight into how religious education remains a space of complex interpretation, rather than a direct translation of the national policy.