The Mentawai Islands in Indonesia are witnessing a unique blend of Indigenous spirituality and world religions among the youth, particularly in their approach to forest management. The ancestral belief system, Arat Sabulungan, teaches that nature is alive with spirits, and this cosmology is being adapted alongside Islam and Christianity. Researchers have identified 11 rituals that link spirituality to environmental practices, such as offerings before tree felling. However, ongoing logging and land-use changes pose significant threats to both the forests and the cultural practices tied to them. The study highlights the resilience of these traditions, as young people actively participate in rituals while navigating modern influences. Despite the pressures, these practices remain vital for maintaining ecological balance and cultural identity, underscoring the need for policies that respect Indigenous rights and wisdom.