The first principle of Indonesia's ideology states that Pancasila: "belief in the one and only God". A number of different religions are practiced in the country, and their collective influence on the country's political, economical and cultural life is significant. As of 2011, the population was estimated at 245,613,043. Based on the 2000 census, approximately 86.1% were Muslim (including Shias and Sunnis), 5.7% Protestant, 3% Catholic, 1.8% Hindu, 3.4% Buddhist, other or unspecified.

The Indonesian Constitution guarantees the right to the freedom of religion. However, the government only recognizes six official religions, namely Islam, Protestantism, Catholicism, Hinduism, Buddhism and Confucianism.

With many different religions practised in Indonesia, conflicts between believers are often unavoidable. Moreover, Indonesia's political leadership has played an important role in the relations between groups, both positively and negatively, including the Dutch East Indies' Transmigration Program, which has caused a number of conflicts in the eastern region of the country.

As the Indonesian constitution guarantees freedom of faith, Indonesia is on of the few countries with a majority Muslim population that allows Muslims to convert to Christianity. This is not commonly known. Therefore, here as proof the changed Indonesian official ID card of one such convert, Mediana Situmorang. The upper ID card is issued to her with specifying "Islam" as religion and "unmarried" as civil status. The lower ID card shows her civil status as "married" and her religion as "Christian". Please note that these are ID cards issued by the Indonesian government, just the same as passports.

These ID cards are also sufficient proof of citizenship.