Fire is the visible focus of Zoroastrian worship and the most misunderstood part of it. It is honoured as the purest of the created elements and as a sign of the divine presence, and prayer is offered in its direction, not to it. Temple fires are graded. An Atash Behram, the highest grade, is consecrated over roughly a year from sixteen separate sources of fire, including one gathered from lightning, and once installed is tended continuously; only a handful exist, mostly in Gujarat and Mumbai. Lesser grades serve ordinary congregations. Priests approach the fire masked, so that breath does not pollute it.
Purity law runs through daily life. Fire, water, earth and air must not be defiled, and the most polluting substance is a corpse. This produced the practice of exposure: the dead are laid on a raised stone structure, a dakhma or tower of silence, where birds strip the bones, so that neither burial nor cremation contaminates earth or fire. The practice has become hard to sustain. Vulture populations across South Asia collapsed in the 1990s after the veterinary drug diclofenac entered the food chain, and Parsi opinion has been divided ever since over solar concentrators, captive aviaries, and whether burial or cremation may be permitted. In most of the diaspora exposure is not an option and burial is normal.
Initiation is the navjote in India and sedreh-pushi in Iran, usually somewhere between seven and fifteen, at which the child receives the sudreh, a white undershirt, and the kusti, a cord of seventy-two threads tied at the waist and untied and retied with prayer several times a day. The Yasna, the principal liturgy, is recited by priests over consecrated implements and includes the preparation of haoma, a pressed plant drink cognate with the Vedic soma.
The most divisive question in the living community is not doctrine but membership. Many Parsi authorities in India accept no converts and do not recognise the children of Parsi women who marry outside the community, while Iranian and North American bodies are often more permissive. Given the demographic decline, that argument is existential rather than academic.