This article explores the sources of Islamic knowledge among young Muslim activists in Bima, Eastern Indonesia, who are often stereotyped as a hotbed of radicalism, and their religious types to reveal their intellectual dynamics. This article argues that, in modern times, as Islamic tendencies and orientations have diversified, young Muslims in the Bima region engage with many different aspects of the production and use of religious knowledge under the umbrella of Indonesian Islam. Moreover, they actively build peer-group-based intellectualism, fostering patron–client connections in the form of discussion and literacy development through student organizations, and this is influential in shaping their religious identities and religious types. This qualitative research involved 47 young Muslim activists, who are also senior high school and university students, 20 of whom were interviewed in-depth, while 27 others participated in focus group discussions. This research reveals that their sources of learning vary. However, the most critical media in shaping and confirming their religious understanding are the training and discussions held by their respective peer groups and organizations. Their literacy and references are also further developed through these forums. Learning resources accessed via social media are considered essential but unreliable in this digital era. Therefore, in their intellectual development, young persons need teachers and families to act as learning resource providers that co-exist with the literacy obtained through organizations. Such sources and ways of learning form a type of religiosity that is “practical” (embodied in daily practice) for most. Meanwhile, the “ideological” type of religion (fundamental to the Islamization movement) is only found in right-wing activists of Islamic organizations and does not thrive among the young people of Bima, Eastern Indonesia.