The tending of a sacred fire, keeping a flame burning continuously as the focus of worship and the presence of the divine, is one of the oldest and most widespread of religious practices, found across many traditions that hold fire to be holy, purifying, and a manifestation or messenger of the divine. In such traditions the fire is not merely a symbol but is treated as sacred in itself, and its maintenance is a solemn duty: to let the sacred flame go out is a grave failing, and specially appointed persons are charged with feeding and guarding it, often under conditions of ritual purity.
The practice takes its most fully developed form in Zoroastrianism, in which fire is revered as the son of the creator and the very emblem of truth and righteousness, and the sacred fires in the fire temples are tended with elaborate care by priests, fed with clean wood and never allowed to be defiled or extinguished; the greatest of these fires are held to have burned for many centuries. In the religion of ancient Rome, the perpetual fire of the goddess Vesta, on whose burning the safety of the state was believed to depend, was guarded by the Vestal Virgins, for whom letting it die was a serious offence. The Vedic tradition of India maintained sacred household and ritual fires into which offerings were poured, some to be kept perpetually alight, and sacred fires figure in the practice of numerous other cultures. Across these traditions the ceaseless flame gives visible, tended form to the conviction that the divine presence abides with the community and must be faithfully kept.