Officially, the name of Bali's religion is Agama Hindu Dharma, which recognises the belief in one god manifested in a variety of forms. The basic foundation of the Hindu deity is the trinity of gods; God the Creator (Brahma), God the Preserver (Visnu) and God the Destroyer (Siva). Along with this trinity, the Balinese place faith in a variety of local gods and ancestors, paralleled to the saints of the Catholic religion. Each temple has shrines to its own local gods, as well as to the 'one true God'.

As well as recognising the power of good in their religion, the Balinese equally acknowledge the power of evil by making offerings each day to the evil spirits as well as the good. The elaborate offerings that may be seen carried on the heads of women to the temple are those for the gods, while offerings to the evil spirits are simply made - small squares of banana leaf holding a few grains of rice, a flower, salt and a pinch of chilli pepper - and set on the ground or steps of a house. Every 15 days, a day called kajeng kliwon according to the Balinese calendar, special offerings are made to the evil spirits as a kind of mini exorcism of any harmful presence.

Most temple festivals are held every 210 days (six Balinese months). However, Nyepi (Balinese New Year) is calculated according to the Lunar Calendar (as is Easter), and falls around March-April each year, the eve of Nyepi corresponding to the night of the new moon. In 2000 Nyepi fell on April 4, when the whole of Bali stopped for a day - no cars or bikes, no smoke from cooking, not a shop open on the whole of the island, just a day for quietude and contemplation after the eve's huge exorcism of evil.
The most important of Bali's festivals in the 210 day cycle is the Galungan/Kuningan festive period. Galungan always falls on a Wednesday, while Kuningan (a 'kajeng kliwon' day) is on Saturday, 10 days later. Galungan and Kuningan are celebrated as a holiday throughout Bali, as are a number of other special days in the Balinese calendar. Then for many festivals, holidays are proclaimed in the area that it is to be celebrated. This means frequent days off for school children who would otherwise have about five weeks off in the middle of the calendar year (the new school year starts here in mid-July), and a week's break between each of the three terms. School is six days a week in Bali, the primary and junior secondary students usually starting at 7.30am through till 1.00pm, when the senior secondary students start, often using the same classrooms as their juniors did in the morning.
Associated with religious festivals and ceremonies are the dramatic arts that most visitors to Bali seek out. The many dances, wayang (puppet) shows and musical performances were generally designed for a particular religious purpose, as well as being part of the local entertainment for ceremonies. Nowadays, however, a selection of these performances can be viewed by visitors, with a regular schedule of dances being performed in the Ubud area for tourists.