82-88% of the population of Indonesia state their religion as being Islam
making it numerically by far the largest religion in the nation and Indonesia the largest Muslim-majority country in the world. Nevertheless, Indonesia officially remains a secular state. Although religious orthodoxies do vary across the Indonesia archipelago the strict observance of Islamic dress codes apparent in some countries is generally absent. In larger cities headscarves and overt manifestations of faith are exceptions rather than the rule. In some regional areas and the devout state of Aceh
things can be considerably stricter. In fact, despite being nominally Muslim, many local stories and customs which are Hindu, Buddhist or animist in origin are faithfully preserved by much of the population.
The other four state-sanctioned religions are Protestantism (5%), Roman Catholicism (3%), Hinduism (2%) and Buddhism (1%). Hindus are concentrated on Bali
, while Christians are found mostly in parts of North Sumatra
, North Sulawesi
, and East Nusa Tenggara
. Buddhism, on the other hand, is mainly practised by the ethnic Chinese in the larger cities. There are also pockets of animism throughout the country, and many strict Muslims decry the casual Indonesian incorporation of animistic rites into the practices of notionally Islamic believers.
Indonesian national law decrees that all citizens of the Republic must declare their religion and that the declared religion must be one of the five that are officially sanctioned by the state. This results in obvious distortions. For example, many animist practitioners notionally call themselves Muslim or Christian for the benefit of the state bureaucracy.