The Ancestral Spirits were divine beings worshiped by the Nechani. The Nechani who devoted themselves to the Spirits were members of the Nechisti Order.
In 2373, Kes was severely injured by a neuroleptic shock she received upon inadvertently entering a Nechisti shrine. Though sympathetic, the Nechani magistrate believed that she had been punished by the Spirits and was beyond help.
Based on the old story of King Nevad, who appealed to the Spirits directly to spare his son's life after a similar accident, Captain Kathryn Janeway participated in a purification ritual to commune with the Spirits to save Kes. During the ritual, she was informed that she should take Kes back into the shrine, and trust the Spirits to return her soul. (VOY: "Sacred Ground")