Within Kejawen, ancestral spirits and supernatural beings are not distant abstractions but living presences that shape the moral, spiritual, and social fabric of daily life. Ancestral spirits are regarded as protective guardians who watch over descendants and communities, mediating between the human realm and higher spiritual realities. They are believed to influence health, fortune, and spiritual development, and thus become a powerful anchor for continuity between past and present generations. Honoring them reinforces family lineage, social cohesion, and proper conduct, so that memory of the ancestors becomes inseparable from ethical life. Through this, the lineage is not merely biological but also spiritual, extending into the unseen world that surrounds and permeates ordinary existence.

These ancestral presences are engaged through a rich ritual life. Communal ritual meals such as the slametan, as well as offerings of food and incense (sesajen), are directed in part to the ancestors in order to seek safety, prosperity, and inner and outer balance. Prayers and remembrance at graves or on special days are understood as ways of maintaining a harmonious relationship, keeping ancestral spirits content and supportive. Communication with them may occur through dreams, meditation, or the work of spiritual specialists, and such contact is sought for guidance, healing, and discernment. In this way, the boundary between the living and the dead is softened, and the family is experienced as an extended community that includes those in the unseen realm.

Alongside the ancestors, Kejawen recognizes a densely populated spirit world that includes guardian spirits of places, nature beings, and other subtle entities. Spirits associated with villages, forests, mountains, springs, large trees, and the sea are believed to guard particular locations and communities, sometimes personified as powerful figures residing in sacred sites. There are also beings linked to Islamic vocabulary, such as jin, as well as local spirits inhabiting trees, rivers, stones, and other natural features, together with more ethereal entities that can interact with humans. These spirits may protect and bless when approached with respect, or cause misfortune, illness, and disturbance if offended or neglected. As a result, proper etiquette, taboos, and ritual courtesy in certain places and times are seen as essential to maintaining harmony.

Engagement with these beings is woven into spiritual practice and inner cultivation. Offerings, incense, and formal prayers are accompanied by meditation, trance, or other contemplative disciplines through which practitioners seek contact, insight, and spiritual power. Some cultivate inner strength and mystical capacity (kesaktian or kasekten) through fasting, asceticism, and disciplined practice, understanding that support from ancestral and local spirits can be part of this empowerment. Healers and spiritual specialists may communicate with both ancestors and other spirits to diagnose problems, restore balance, and protect against malevolent influences. Through all of this, Kejawen seeks rukun—harmony—between humans, nature, and the unseen, so that the visible and invisible worlds remain in dynamic but balanced relationship.