Shona Mwari (literally "He or she who is"), or Ndebele uMlimu are both believed to be active in the everyday lives of people. In general, people communicate ith Mwari through the vadzimu (Shona), or amadhlozi (Ndebele). These are the deceased ancestors. The vadzimu are believed to constitute an invisible community within the community of the living, always around their descendants, caring for them and participating in their joys and sorrows. Spirit mediums communicate with the vadzimu on behalf of the people.
In Shona religion, in addition to the guarding characteristics of the vadzimu, there are also the avenging, ngozi, and those who communicate with them. The ngozi are the spirits of deceased individuals who were greatly wronged, neglected by a spouse, murdered, or otherwise neglected. They attack through sudden death of members of the same family or through illness that fails to respond to treatment. The ngozi are the balancing force that are in place to deal with human wrong doing.
Communication between the living and the dead is taken care of by the spirit mediums who are vital parts of Shona culture and religion. The role of the spirit mediums and their communication with and appeasement of the ancestors are acting as intermediaries between Mwari/uMlimu and the living, carrying messages, prayers and thanks from the human being to God. Where ancestors are subject to appeasement by human beings, it is believed that God is appeased as well.
One reveres the vadzimu as they are the direct contact with Mwari. The spirit mediums "intercede between you and the ancestral spirits. The ancestral spirits who intercede will carry it forward to God, because we also believe in God."